part
Latinpart, divide, share
About This Root
The root part comes from Latin pars, partis, meaning "a part, a portion, a share." Picture a Roman dividing up a piece of land, a loaf of bread, or the spoils of war — every slice is a pars. From the same family came the verb partīrī, "to divide or share out," the action of cutting the whole into pieces and handing them around.
This single idea — a whole broken into pieces — branches out in three directions.
First, the literal "piece" sense. A part is a portion of a whole (part of the cake, spare parts of a machine). Make it tiny and you get particle, originally a "little part" — which is why physicists borrowed it for the smallest pieces of matter. Add a prefix and you describe what is done to the pieces: partition (di- the act of dividing into parts), compartment (a space walled off into a separate part), apart (away into pieces).
Second, the "separate, leave" sense. To depart is literally to "divide oneself away" from a place — separation became the everyday word for leaving. This is also where the confusion with the look-alike root port (carry) begins: depart (part = separate, leave) is NOT deport (port = carry away, expel). Same spelling halfway through, opposite ideas.
Third, the "side, faction, share" sense. If you take a part in something, you are involved in it: participate is part + capere ("to take") — literally "to take a share." A party is a group that holds one side or share of an affair (a political party, a party to a contract). To be partial is to lean toward one part — hence both "incomplete" (only part) and "biased" (favoring one side); impartial undoes the bias. A partner shares the work, a counterpart matches you on the other side, and to impart is to give someone a share of what you know.
A special branch comes straight from partīrī (to share out): portion is a share or serving, and proportion (pro- + portion) is how shares relate to one another — the balance of part to part. The whole proportion family (proportional, disproportionate) belongs here, with part, not with the carry-root port, even though they look alike.
The pattern to hold onto: wherever you see part, something is being broken into pieces, separated, or shared out. The prefix tells you the twist — de- (away → leave), com- (together → walled into sections), im-/in- (in → give a share / not biased), pro- (forward → in balanced relation).
Think of cutting a pizza into parts: every slice is a part, you take part by grabbing one (participate), and a tiny crumb is a particle. The trick is not to confuse part (divide) with its twin port (carry): you depart (leave, divide away) at the airport, but you deport (carry away) a person. Splitting → part; moving → port.
Core Words Deep Dive
The few words from this family worth telling in full — one by one.
The bare root living as an English word. As a noun it is 'a piece of a whole' (part of the plan, car parts); as a verb it keeps the older Latin sense of 'divide/separate' — to part the curtains, to part one's hair, lovers parting ways. So the single word part already contains the root's two faces: the static 'a portion' and the active 'to divide.' The phrase 'take part' (participate) and 'play a part' (a role, originally an actor's portion of the script) both grow straight from it.
A hidden compound. part (a share) + capere (to take) → 'to take a share.' When you participate, you are not just present — you take part, you grab a piece of the activity and make it yours. The same capere ('take') hides inside the related forms participant ('one taking a share') and participation. Knowing the buried 'take' is what separates participate (actively take part) from merely attend (just be there).
From Latin particula, a 'little part' (the same diminutive that gives us particle). If you zoom in on one small part of a whole rather than the general mass, you are looking at the particular — hence 'specific, individual.' From 'attending to small parts' came the sense of being fussy: a particular person cares about tiny details. The adverb particularly ('especially') means 'with attention to this one part above the rest.'
Not a- + part as you might guess, but a loop through Italian. Italian appartare meant 'to separate, to set apart,' and an appartamento was a set of rooms 'set apart' for one household within a larger building. French apartement and then English apartment kept the idea: your own partitioned-off section of a building. So under the modern flat lies the old root sense — a part separated from the whole.
pro- ('for, according to') + portion (a share, from partīrī) → 'each according to its share.' Proportion is the relationship between shares — how the size of one part compares to another or to the whole. This is why we say 'in proportion to' (matched share for share) and 'out of proportion' (the shares no longer fit). Note: despite looking like the carry-root port words, proportion belongs to part — it is about dividing and balancing shares, not carrying.
Related Roots
Associated Words · 68
all-party
Involving all political parties
anti-apartheid
Opposed to racial segregation, especially as practised in South Africa
apart
Separately or at a distance; into pieces; distinct from others
apartheid
A system of racial segregation and discrimination; to impose such a policy
apartheid-era
Relating to the period of apartheid rule
apartment
A self-contained home within a larger building; a flat
auto-parts
Components or spare parts for automobiles
bipartisan
Involving or supported by two political parties
bipartisanship
Cooperation between two political parties
co-partner
A joint partner in a business or venture
cocktail-party
An informal social gathering with cocktails
compartment
A separate enclosed section within a larger space
counterpart
A person or thing with the same role or function as another in a different context
depart
To leave a place or set out on a journey
departed
Having left or died; a person who has died
department
a division of an organization with a specific function
department-store
A large shop with sections selling many types of goods
departmental
Of or relating to a department
departure
The act of leaving; a deviation from a plan
dinner-party
A social gathering for a formal evening meal
disproportion
A lack of balance or proportion; an imbalance
disproportional
Not in proper proportion; unbalanced
disproportionate
Too large or small relative to something else; not in proper proportion
impart
To give or pass on knowledge, a quality, or information
impartial
Treating all sides equally and fairly; unbiased
impartiality
The quality of being fair and unbiased
impartially
In a fair and unbiased manner
impartible
Not subject to division; indivisible
major-party
A large, influential political party
multi-party
Involving multiple political parties or groups
nanoparticle
A microscopic particle under 100 nanometers in size
non-participant
A person who does not take part in an activity
non-participation
The act of not taking part in something
non-party
Not affiliated with any political party
nonpartisan
Not aligned with any political party; impartial
nonpartisanship
The quality of being politically independent and impartial
part
a portion of something; to separate
part-time
Working or done for fewer hours than a full schedule
part-timer
A person who works part-time
partial
Incomplete or affecting only part of something; biased or unfair
partiality
Unfair bias toward one side; a special fondness for something
partially
To some extent but not completely
partible
Capable of being divided or partitioned
participant
A person who takes part in an activity or event
participants
People who take part in an activity or event
participate
To take part or become involved in an activity
participation
The act of taking part in something
particle
A very small piece of matter; a subatomic unit; a grammatical function word
particular
specific or special; a specific detail
particularity
The quality of being specific; a distinctive detail
particularly
especially; to a notable degree
parties
Social gatherings; political organizations; groups in a legal matter
partisan
A strong supporter of a party or cause; biased in favor of a group
partisanship
Biased support for a particular party or group
partition
To divide into parts; a wall dividing a space; a hard disk section
partly
To some extent but not completely
partner
A person who shares an activity or relationship; to work together
partnership
A cooperative relationship or jointly run business between partners
party
a social gathering; a political group; one side in an agreement
portion
A part or share of something; a serving of food; 部分；一份
pro-apartheid
Supporting racial apartheid
proportion
A part of a whole amount; the relative size or balance between things; to arrange in proper shares
proportional
Corresponding in size or degree; in a constant ratio
proportionate
Corresponding in size or degree; in proper proportion
single-party
Relating to a political system with only one party
spare-parts
Extra components kept to replace broken parts
subpart
A section forming part of a larger part
unproportional
Not in proper proportion