early 15c., plenarie, "full, complete," earlier plenar (mid-13c.), from Old French plenier and directly from Medieval Latin plenarius "entire, complete," from Latin plenus "full, filled, greatly crowded; stout, pregnant; abundant, abounding; complete," from PIE root *pele- (1) "to fill." Of an assembly, "fully attended," 1530s. Meaning "having full power" is from 1861. Related: Plenarily.
"muddy, turbid, full of dregs or impurities," late 15c., from Latin faeculentus "abounding in dregs," from stem faec- "sediment, dregs" (see feces) + adjective suffix -ulentus "full of." Related: Feculence.
1670s, "filled space, the fullness of matter in space" (opposite of vacuum), from Latin plenum (spatium) "full (space)," neuter of adjective plenus "full, filled, greatly crowded; stout, pregnant; abundant, abounding; complete," from PIE root *pele- (1) "to fill." Used to denote fullness in general, hence the meaning "of a full assembly of legislators" is recorded by 1772.
"being full to the brim," 1660s, present-participle adjective from brim (v.).
"tightly, close up against," 1799, back formation from chock-full.
word-forming element attached to nouns (and in modern English to verb stems) and meaning "full of, having, characterized by," also "amount or volume contained" (handful, bellyful); from Old English -full, -ful, which is full (adj.) become a suffix by being coalesced with a preceding noun, but originally a separate word. Cognate with German -voll, Old Norse -fullr, Danish -fuld. Most English -ful adjectives at one time or another had both passive ("full of x") and active ("causing x; full of occasion for x") senses.
It is rare in Old English and Middle English, where full was much more commonly attached at the head of a word (for example Old English fulbrecan "to violate," fulslean "to kill outright," fulripod "mature;" Middle English had ful-comen "attain (a state), realize (a truth)," ful-lasting "durability," ful-thriven "complete, perfect," etc.).