がいっぱい

full of; overwhelmed with

→ が
phrase Uncommon #12,722
full of; overwhelmed with Used after a noun to say there is a lot of something or that something is full. In expressions such as 胸がいっぱい and 頭がいっぱい, it means being overwhelmed with emotion or having one's mind full of something.
JA: 公園は子どもたちがいっぱいだ。
EN: The park is full of children.

アフリカ自然がいっぱい

Africa is full of nature.

口にクラゲがいっぱい

There are lots of jellyfish in my mouth.

— 甘い生活 (1960)

この問題には心理的また経済的難問がいっぱい

This issue is fraught with both psychological and economic difficulties.

その公園にはリスがいっぱいいました

There were lots of squirrels in that park.

東京ミッドタウンがいっぱい

Tokyo Midtown is full of greenery!

流しがいっぱいだったのでお皿流しの横に置いておきました

The sink was full, so I left the dishes next to it.