1.
full, filled
Completely filled to capacity.
電車は人で一杯だった。
The train was full of people.
お腹一杯食べた。
I ate until I was full.
駐車場が一杯で車を止められなかった。
The parking lot was full and I couldn't park.
2.
one cup/glass of
A serving of liquid in a cup or glass.
ビールを一杯ください。
One beer, please.
コーヒーを一杯飲んだ。
I had a cup of coffee.
仕事の後に一杯いかがですか。
How about a drink after work?
3.
a lot, many
A large quantity or number.
宿題が一杯ある。
I have a lot of homework.
花が一杯咲いている。
Lots of flowers are blooming.
今日はやることが一杯あって、休む時間がない。
I have so much to do today that I don't have time to rest.
一杯 has multiple meanings.
1. FULL:
- お腹一杯: stomach is full
- 人で一杯: full of people
2. ONE CUP/GLASS:
- コーヒー一杯: one cup of coffee
- 一杯いかが?: How about a drink?
3. A LOT:
- 一杯ある: there's a lot
- 一杯食べる: to eat a lot