tain
Latinhold, keep
About This Root
The root tain comes from Latin tenēre, "to hold, to keep, to grasp." Picture a hand closing around something and not letting go — that single gesture is the heart of the entire family. Whatever a tain word is doing, it is keeping a grip on something.
The magic happens when prefixes tell you how or in what direction the holding goes:
- con- (together) + tain → contain: hold things together inside one space. A box contains; a country contains its borders.
- re- (back) + tain → retain: hold something back, keep it from leaving. You retain water, retain staff, retain the right.
- ob- (toward, onto) + tain → obtain: get a hold of something through effort — reach out and grasp it.
- sus- (a form of sub-, from below) + tain → sustain: hold something up from underneath so it keeps going.
- de- (away, aside) + tain → detain: hold someone back/aside, stop them from moving on.
- abs- (away) + tain → abstain: hold yourself away from something.
- per- (through, thoroughly) + tain → pertain: hold all the way through to a matter — to be connected to it.
Two members hide their prefix. maintain comes from Old French maintenir, from Latin manū tenēre — literally "to hold in the hand" (manus = hand). So the main- in maintain is not "main/chief" at all; it is the worn-down ghost of manus, the hand that keeps things in good order. entertain comes from inter- (between) + tenēre: "to hold between/among" — originally to keep someone in a certain state of mind, to hold their attention. Holding an audience's attention is exactly what entertainers still do.
On the surface the root changes shape. After a prefix and before a vowel it usually appears as tain (contain, retain, obtain). Inside longer words and in older formations it flattens to ten (continent, continuous, abstinent) or tin (continue, continuity), and the past-participle form tentum gives tent (content, contented, discontent). They all trace back to the same closed hand.
The pattern to remember: the root tain/ten/tin/tent is always "hold/keep," and the prefix tells you which way the holding points — together, back, toward, from below, away.
Think of a closed hand holding tight — tenēre means "to hold." A container holds things together (con-), to retain is to hold back (re-), to obtain is to get a hold of something. Even maintain is the same root hiding a hand: main- is Latin manus, so to maintain is literally to keep something "in hand."
Core Words Deep Dive
The few words from this family worth telling in full — one by one.
contentTwo completely different words spelled the same, split by stress.
Two completely different words spelled the same, split by stress. CON-tent (noun, stress on first syllable) = what is held inside: the content of a box, video content. con-TENT (adjective/verb, stress on second syllable) = held together and at rest, hence satisfied — your desires are 'contained,' nothing spills over wanting more. Both come from con- (together) + tenēre (hold): one holds material inside, the other holds your wishes in check.
Open contentmaintainThe hidden hand.
The hidden hand. main- is not English 'main'; it is Latin manus (hand) worn down through Old French maintenir, from manū tenēre = 'to hold in the hand.' To maintain a road, a position, or a claim is to keep your hand on it so it doesn't fall apart. The 'assert/claim' sense (maintain that...) is the same image: you keep holding to your statement even under pressure.
Open maintaincontinuecon- (together) + tin (hold) = to hold things together across time, with no gap.
con- (together) + tin (hold) = to hold things together across time, with no gap. The whole continu- family branches from this: continuous (no break at all), continual (holding on but with repeated pauses), continuity (the unbroken thread), continent (originally 'holding together' — a landmass held together as one piece).
Open continuesustainsus- (a form of sub-, 'from below') + tain (hold) = to hold up from underneath so something keeps going.
sus- (a form of sub-, 'from below') + tain (hold) = to hold up from underneath so something keeps going. Picture a hand under a sagging beam. From that physical image come all its senses: sustain life (keep it going), sustain growth (keep it up over time), and even sustain an injury — the odd one out, where you 'undergo/bear' the blow rather than support it.
Open sustainentertaininter- (between/among) + tenēre (hold) = to 'hold between,' originally to keep someone in a state of mind.
inter- (between/among) + tenēre (hold) = to 'hold between,' originally to keep someone in a state of mind. Three senses survive: hold an audience's attention (amuse), hold guests (host them), and hold an idea in mind (entertain a thought/possibility). All three are about keeping something — attention, people, or an idea — in your grip.
Open entertainRelated Roots
Associated Words · 87
continue
To proceed with (doing an activity); to prolong (an activity); An option allowing a gamer to resume play after game over, when all lives have been lost
maintain
to keep up or preserve; to assert as true; to repair
contain
To hold inside
obtain
To get or acquire something through effort
content
Subject matter or material (n.); satisfied (adj.); to satisfy (v.)
entertainment
Activities or performances designed to amuse or interest people
retain
To keep or continue to have something
sustain
To maintain or keep going; to provide nourishment or support
maintenance
Work done to keep something in good condition; financial support after divorce
container
An object used to hold things; a large metal shipping box
continuous
Going on without stopping or interruption
continent
One of the seven main landmasses of the Earth; exercising self-restraint
sustainable
Able to be maintained long-term without harming the environment
entertain
To amuse an audience; to host guests; to consider an idea
tenure
The period of holding a position; a permanent academic post
attain
To achieve or reach a goal through effort
continually
Repeatedly and frequently; without apparent interruption
tenant
A person who pays rent to use property owned by another
lieutenant
A junior military officer rank; a deputy or assistant to a superior
continuity
Uninterrupted connection or consistency over time
retention
The act of keeping something; the ability to remember information
continuously
Without stopping or pausing
detain
To hold someone in custody; to delay or hold back
continuum
A continuous series where no part is sharply distinct from adjacent parts