pocketful (n.)

mid-14c., pokete, "small bag or pouch, small sack," from Anglo-French pokete (13c.), diminutive of Old North French poque "bag" (Old French pouche), from a Germanic source akin to Frankish *pokka "bag," from Proto-Germanic *puk- (see poke (n.1)).

The narrower meaning "small bag worn on the person, especially one sewn into a garment" is from early 15c. The sense of "one of the small bags or nets at the corners and sides of some billiards tables" is from 1754. The mining sense of "cavity in the ground filled with ore" is attested from 1850; the military sense of "area held by troops almost surrounded by the enemy" is from 1918; the general sense of "small area different than its surroundings" (1926) apparently was extended from the military use.

Figuratively, "one's money" (conceived as being kept in a pocket), from 1717; hence to be out of pocket "expend or lose money" (1690s); Pope Pokett (late 15c.) was figurative of the greedy and corrupt Church.

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.).