noun, noun which may take the genitive case particle 'no'
one cup; one glass; one bowl; one spoonful
Counter for a single container or spoonful of something. Used with の to modify nouns.
コーヒーを一杯ください。
One cup of coffee, please.
彼はご飯を一杯食べた。
He ate one bowl of rice.
noun
Specifically one serving of an alcoholic beverage. Often used in social contexts.
一杯やりませんか。
How about a drink?
na-adjective, noun which may take the genitive case particle 'no', noun, used as a suffix
full; filled; brimming; crowded; packed
Describes a state of being full to capacity, often used with に or の. Usually written in kana.
会場は人でいっぱいだった。
The venue was packed with people.
お腹がいっぱいです。
I'm full.
adverb, noun, used as a suffix
fully; to capacity; as much as possible
Adverbial use meaning to the maximum extent. Usually written in kana.
時間をいっぱいに使って仕上げた。
I used the time to the fullest to finish it.
adverb
Adverbial use indicating a large quantity or degree. Usually written in kana.
今日は仕事がいっぱいある。
I have a lot of work today.
noun, used as a suffix, adverb
all of ...; the entire ...
Suffix-like use meaning the whole of something. Usually written in kana.
彼は一年いっぱい海外にいた。
He was abroad for the entire year.
noun
one (squid, octopus, crab, etc.)
Counter for certain seafood items like squid, octopus, and crab, often used in markets or cooking.
イカを一杯買った。
I bought one squid.
noun
Counter for boats. Less common than 隻 (せき) but used in some contexts.
港に船が一杯泊まっている。
One boat is anchored in the harbor.