pel
Latinpush, drive
About This Root
The root pel comes from Latin pellere, "to push, drive, or strike" — the action of shoving something so it moves whether it wants to or not. Its past participle was pulsus, which is why half the family is spelled pel- (the live verb) and the other half puls- (the result). Picture a single shove. Then watch a prefix point that shove in a direction, and you get almost the whole family:
- ex- (out) + pellere → expel: drive someone out (out of school, out of the country, out of your lungs).
- re- (back) + pellere → repel: push back — an army repels attackers, and figuratively a smell or a person pushes you back, i.e. disgusts you.
- pro- (forward) + pellere → propel: push forward — exactly what a propeller and rocket propulsion do.
- in-/im- (in, on) + pellere → impel: push someone into action, an inner shove. The noun impulse is that single push felt from inside — a sudden urge to act before thinking.
- com- (together, intensifier) + pellere → compel: push with full force until there's no choice — to force. Compulsory schooling is schooling you are pushed into; a compulsion is an inner push you can't resist.
- dis- (apart) + pellere → dispel: drive apart and away — you dispel doubts and fears, scattering them.
The puls- branch keeps the literal beat of pushing. A pulse is the heart pushing blood, felt as a throb; to pulsate is to keep beating. Every -sion noun (expulsion, propulsion, repulsion, compulsion) is just the puls- form of its verb.
One corner of the family takes a detour through French. Latin ad- (toward) + pellere gave appellare, "to address or call upon someone" — to push your words toward a person. From there English got appeal (to call earnestly upon someone, then to call upon a higher court) and the legal terms appellate, appellant, plus appellation (the name you call something). Repeal is re- + appeal — to call something back, i.e. to cancel a law. The connection to "push" is faint here, but the thread is the same: directing force or a call at someone.
The rule of the family: pel/puls is always a shove. The prefix tells you which way it goes — out, back, forward, in, or together — and puls- is just the spelling that shows up in the noun.
Think of a single push, then aim it: ex-pel pushes out, re-pel pushes back, pro-pel pushes forward, im-pel pushes you from inside (an im-PULSE), and com-pel pushes so hard you have no choice. The -sion / pulse spellings are just the same push frozen as a noun.
Core Words Deep Dive
The few words from this family worth telling in full — one by one.
com- (an intensifier here, 'completely') + pellere (push) = to push someone completely, until resistance is gone — to force. The intensity is the whole point: you don't 'compel' someone gently. Note the adjective compelling drifted to mean 'so forceful it grabs you' — a compelling story or compelling evidence pushes you toward a conclusion you can't resist.
im- (in) + pulsus (a push) = a push felt from inside. That's exactly what an impulse is — a sudden inner shove to act before you've thought it through (buy on impulse). The same image works in physics (an impulse is a brief push that changes motion) and in electronics (an electrical impulse). One picture, three fields.
re- (back) + pellere (push) = push back. Literally an army repels an invasion; a coating repels water. The leap is emotional: when something 'pushes you back,' you feel disgust or aversion — his attitude repels me. So the adjective repulsive means 'so off-putting it shoves you away.' Physics keeps the literal sense: like charges repel.
pro- (forward) + pellere (push) = push forward. The most literal member: a propeller and rocket propulsion both push a vehicle forward. The figurative use is just as direct — the scandal propelled her to fame, the news propelled the stock upward. Whenever something is driven ahead by a force, it's propelled.
ad- (toward) + pellere (push) went through Latin appellare 'to address, call upon' and Old French, so the 'push' faded into 'direct words toward someone.' Three modern senses branch from that: call earnestly upon people (appeal for help), call upon a higher court (file an appeal), and — the surprise — 'attract,' because something appealing calls out to you and pulls your interest in. One root act: aiming a call at someone.
Related Roots
pel/puls is to push or drive away; tract is to pull or drag toward (attract, extract, tractor). repel (push back) vs attract (pull toward) is the cleanest pair — they're literally the two opposite forces.
Not a separate root — puls is just the past-participle spelling of pellere. Every -sion noun (expulsion, compulsion, propulsion) and pulse/pulsate use it. If you see puls-, think 'the noun form of a pel- verb.'
Look-alike but unrelated: pel/puls = push, drive; pend = hang, weigh (suspend, pendant, depend). The word suspender belongs to pend (hang up trousers), not to pel. Pushing → pel; hanging or weighing → pend.
Associated Words · 52
appeal
An earnest request or legal review; to attract or interest someone
appealing
Attractive or interesting; arousing a favorable response
appealingly
In an attractive or pleasing manner
appellant
A person who makes a legal appeal; relating to appeals
appellate
Relating to the hearing of legal appeals
appellation
A name or title by which someone or something is known
compel
To force or pressure someone to do something
compellable
Capable of being compelled or legally forced
compeller
One who forces or compels others to act
compelling
Extremely interesting or convincing; forcefully demanding attention
compellingly
In a convincing and forceful manner that is hard to resist
compulsion
An irresistible urge to act; the use of force to make someone do something
compulsive
Driven by an uncontrollable urge; unable to stop a behaviour
compulsively
In an obsessive, uncontrollable manner
compulsiveness
The quality of being compulsive or obsessive
compulsory
Required by law or rules; obligatory
dispel
To drive away or eliminate doubts, fears, or misconceptions
expel
To force someone to leave a place or organization
expellable
Capable of or deserving expulsion
expellant
Having the power to expel; a substance that drives out unwanted material
expellee
A person who has been expelled
expeller
Someone or something that expels
expulse
To expel or drive out by force
expulsion
The act of forcing someone out of a place or organization
impel
To urge or drive someone to act; to propel forward
impeller
A rotating blade that drives fluid forward
impulse
A sudden urge to act; a sudden driving force
impulsion
A driving force or sudden urge that moves someone to act
impulsive
Tending to act without thinking; driven by impulse
impulsively
Acting on sudden urges without careful thought
impulsiveness
The tendency to act on impulse without reflection
propel
To drive or push something forward with force
propellant
A substance used to propel something forward
propellent
Capable of propelling; a substance that propels
propeller
A rotating blade device that moves an aircraft or boat
propeller-driven
Powered by a propeller
propulsion
The force or process that drives something forward
propulsive
Having the power to propel something forward
pulsate
To beat or throb rhythmically
pulsation
A rhythmic beat or throb, as of the heart
pulse
The regular beat of the heart or arteries; to throb rhythmically
repeal
To officially cancel a law; the act of cancelling a law
repel
To drive back an attack; to cause disgust or aversion; to push away by force
repellant
Causing disgust; a substance that drives away insects
repellence
The quality of repelling or causing aversion
repellent
A substance that drives away pests or repels water; causing disgust or aversion
repulse
To drive back or repel; to cause disgust; a rejection
repulsion
Strong disgust or aversion; a force pushing things apart
repulsive
Causing strong disgust; extremely unpleasant
rocket-propelled
Driven by a rocket engine
unappealing
Not attractive or interesting
water-repellent
Resistant to water penetration; 拒水的，防水的