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.
He ate one bowl of rice.
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.
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.
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.
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.
One cup of coffee, please.
I ate rice and became full.
I ran with all my strength.
There are a lot of books.
The train was packed with people.
たくさん is the neutral, standard word for 'a lot', while 一杯 is more colloquial and often implies fullness or being packed as well as sheer quantity.
一杯 is a casual, general word for having a drink (not necessarily at home), whereas 晩酌 specifically means the evening drink taken with one's dinner at home.
満々 is a formal たる-adjective used mainly with abstract nouns like 自信 or やる気, while いっぱい is the everyday word for something being full, physically or figuratively.
いっぱい is a native Japanese word for 'full' used broadly in everyday speech, while フル is a loanword that stresses maximum extent and appears often in compounds like フル回転.
いっぱい is a casual word for 'a lot' or 'full', whereas たっぷり can be used in slightly more formal contexts and often implies roominess or generosity rather than just quantity.
いっぱい is a casual, everyday word for 'full' or 'a lot', while 満載 is more formal and implies a deliberate loading or rich content.
いっぱい is a casual word meaning 'full' or 'a lot', close in feel to うんと but without うんと's extra emphasis on degree.
いっぱい stresses that a container or space is full, whereas どっさり focuses on the sheer bulk or weight of the amount itself.
空っぽ means completely empty, the opposite of 一杯 meaning completely full.
一杯 means 'full' and is the natural opposite of 空 when describing a container, cup, or schedule slot with nothing left in it.
からから describes a container or space as completely empty, while いっぱい describes it as completely full.
一敗 is a homophone of 一杯 but means 'one defeat/loss' in a game or match, with no connection to cups or fullness.
一泊 sounds very similar to 一杯 but means 'one night's stay' at a hotel or inn, an unrelated meaning.
一杯 means 'a cup (of something)' or 'full/plenty', while 精一杯 (built on the same kanji) means 'one's utmost effort' — don't confuse the two despite the shared 一杯.
one's best; the best one can do · with all one's might; as hard as possible
having one's hands full; at the limit; fully occupied
to the limit; as much as possible; with all one's might
to the limit; at one's limit; breaking even · one cup after another; cup by cup
tipsy; a little drunk; slightly intoxicated
cheap drinking spot; inexpensive pub or tavern
Numerical variant using １ instead of 一; common in horizontal writing.
Outdated kanji form; 盃 is a variant of 杯.