puff up
Upper Intermediate (B2)neutral
to get bigger and rounder, or make something sound better than it is
"Her eyes puffed up after she touched the cat."
Hear it in context

Diving with Great White Sharks All Around Us!
Brave Wilderness Top Videos · 25:18
Puff up.

Diving with Great White Sharks All Around Us!
Brave Wilderness Top Videos · 25:19
Puff up.

Epic Animal Wars | Animal Fight Night S2 & S6 MEGA Episode | Nat Geo Animals
Nat Geo Animals · 77:05
Neck feathers puff up to intimidate.

Crash Course Astronomy Marathon • Full Series
CrashCourse · 406:43
But when they do, they puff up.

These Kati Rolls are One of India's Best Street Foods | Street Eats | Bon Appétit
Bon Appétit · 4:38
It's trying to puff up a little bit