ple
Latinfill, full
About This Root
The root ple comes from Latin plēre, 'to fill,' and its twin adjective plēnus, 'full.' Both trace back to the ancient PIE root pleh₁-, 'to fill' — the same source that gives English the native word full and the prefix plus*. The whole family is built on one simple image: a container, and how full it is.
Start with an empty vessel and the prefixes tell you what happens to it:
- com- (completely) + plēre → complete: to fill it up entirely. Nothing missing, nothing left out — that's what 'complete' means. From there: completion (the act of filling up), incomplete (not yet full).
- de- (away, down) + plēre → deplete: to drain it back out. Your resources, your energy, the ozone layer — when something is depleted, the vessel has been emptied. Hence depletion.
- re- (again) + plēre → replenish (via Old French re-plenir) and replete: to fill it again, to make it full once more. A replenished stockroom; a book replete with examples.
- sup- (sup-, from below) + plēre → supplement: to fill in from underneath, to top up what's lacking. A dietary supplement fills a gap in your diet.
- com- + plēre → complement: to fill out and make whole. Two things that complement each other each supply what the other lacks. (Compare complementary colours — together they complete the spectrum.)
From plēnus 'full' comes the abundance branch: plenty, plentiful, and the Greek-flavoured plethora, which originally meant an over-full state (too much blood in the body) and now just means 'an excessive amount.' The little word plus ('more') is plēnus's close cousin too.
Two warnings. First, compliment (a flattering remark) is the same word as complement historically — both 'fill up / round out' — but split apart, so today complement = completes a whole, compliment = praises a person. They're a classic spelling trap. Second, and bigger: a huge set of look-alike words — complicate, imply, reply, comply, multiple, simple, ply — do not belong here. They come from Latin plicāre, 'to fold,' a completely different root (now housed under plic). 'Simple' = 'one-fold,' not 'one-fill.' If the idea is folding/bending, it's plic; if the idea is filling/fullness, it's ple.
Think of a glass and how full it is. complete = filled up to the brim, deplete = drained empty, replenish = topped back up, plenty = overflowing. Every ple- word is about the level in the container. (Don't confuse it with plic = 'fold' — simple/reply/complicate live there.)
Core Words Deep Dive
The few words from this family worth telling in full — one by one.
completecom- (completely) + plēre (fill) = 'filled up entirely.' This is the cleanest window onto the root: 'complete' literally means there's nothing left to fill in.
com- (completely) + plēre (fill) = 'filled up entirely.' This is the cleanest window onto the root: 'complete' literally means there's nothing left to fill in. The whole abundance vocabulary spins out from this filling image — completion is the filling done, incomplete is the filling unfinished.
Open completedepletede- (away) + plēre (fill) = literally 'un-fill,' to empty out.
de- (away) + plēre (fill) = literally 'un-fill,' to empty out. It's the exact opposite move from complete: instead of filling the vessel, you drain it. That's why we speak of depleted resources, depleted energy, ozone depletion — the tank has been run down.
Open depletesupplementsup- (from below) + plēre (fill) = 'to fill up from underneath,' to top up what's missing.
sup- (from below) + plēre (fill) = 'to fill up from underneath,' to top up what's missing. A dietary supplement fills a nutritional gap; a salary supplement tops up income; a newspaper supplement adds extra pages. Always: something added to fill a shortfall.
Open supplementplentyStraight from plēnus 'full,' via Old French plenté 'abundance.' If a container is full, you have plenty — more than enough.
Straight from plēnus 'full,' via Old French plenté 'abundance.' If a container is full, you have plenty — more than enough. The same plēnus gives plentiful and the over-full plethora, and is cousin to plus. Plenty is the everyday face of the 'fullness' branch.
Open plentycomplementcom- + plēre = 'to fill out, make whole.' Two things that complement each other each supply what the other lacks, completing the set.
com- + plēre = 'to fill out, make whole.' Two things that complement each other each supply what the other lacks, completing the set. Historically the very same word as compliment (a praise) — they split, so now complement = completes, compliment = praises. A classic spelling trap.
Open complementRelated Roots
Identical-looking but unrelated. ple comes from plēre 'to fill' (complete, deplete, plenty). plic comes from plicāre 'to fold' (complicate, imply, reply, multiple, simple). Quick test: about fullness/level → ple; about folding/bending/layering → plic.
Both touch on 'enough / full.' ple is about a vessel being physically filled to capacity (replete, plenty). sat (from satis 'enough') is about being satisfied or saturated — having had enough. Filled to the top → ple; had enough → sat.
Associated Words · 42
completely
(manner) In a complete manner
complete
To finish; to make done; to reach the end; A completed survey; With all parts included; with nothing missing; full
supply
to provide for use; an available amount of something
plenty
A large, sufficient amount; more than enough
plus
Added to; and also; a positive advantage
implement
To carry out a plan or decision; a tool for a specific task
accomplish
To successfully complete or achieve something
implementation
The process of putting a plan or system into effect
accomplishment
Something successfully achieved; a skill acquired through effort
completion
The act of finishing or accomplishing something
supplement
Something added to improve or complete; to add to something
complement
Something that completes another thing; to enhance by providing what is lacking
incomplete
Not finished or lacking necessary parts
compliment
A remark expressing praise; to express admiration to someone
complementary
Completing or enhancing each other; forming a whole together
plentiful
Existing in large amounts; abundant
deplete
To use up or significantly reduce a resource
supplemental
Added to supplement or make up a deficiency
depletion
The exhaustion or using up of a resource
replenish
To refill or restore a supply that has been used up
complimentary
Expressing praise; given free of charge
replete
Abundantly filled or supplied; completely full
plethora
An excessive or very large amount
plural
The grammatical form referring to more than one; consisting of more than one