noun, takes genitive case の

  1. one cup (of), one glass (of), one bowl (of), cupful, glassful, bowlful, spoonful.

noun

  1. one drink (of alcohol).

adjectival noun or quasi-adjective, takes genitive case の, noun used as a suffix

Usually written with kana alone.
  1. full, filled (with), brimming (with), crowded, packed.

adverb, noun used as a suffix

Usually written with kana alone.
  1. fully, to capacity, to the maximum, as much as possible.

adverb

Usually written with kana alone.
  1. a lot, much, many.

noun used as a suffix, adverb

Usually written with kana alone.
  1. all of ..., the entire ....

noun

  1. one (squid, octopus, crab, etc.).
  2. one (boat).

Variations

Pronunciation Kanji Kana Is Common
一杯 いっぱい
1杯 いっぱい
 
 
一ぱい いっぱい
 
 
1ぱい いっぱい
一盃 いっぱい

Contained Kanji Breakdown

one, one radical (no.1)
イチ いっ ひと- (1st, N5)
counter for cupfuls, wine glass, glass
ハイ さかずき (7th, N3)
tree, wood
き モク こ- (1st, N5)
negative, non-, bad
 (4th, N4)
cliff (厂) variant
divining, fortune-telling, divination or katakana to radical (no. 25)
ボク うらな.う うらない (Kentei Pre-1)