Translation guide
The English phrase 'puff up' has several distinct meanings: to swell physically, to become arrogant, and to inflate something. This guide covers natural Japanese expressions for each.
Describing something that expands in size, often due to air, heat, or injury.
Intransitive verb meaning 'to swell' or 'to expand'. Used for bread, balloons, cheeks, etc.
パンがオーブンで膨らんだ。
The bread puffed up in the oven.
風船が膨らむ。
The balloon puffs up.
Specifically for body parts swelling due to injury or inflammation.
足首が腫れている。
My ankle is puffed up.
Similar to 膨らむ but often implies a more noticeable or abnormal swelling, or can be used for sulking.
ご飯が水を吸って膨れた。
The rice absorbed water and puffed up.
Technical term for expansion, often used in scientific contexts.
気体は熱で膨張する。
Gases puff up (expand) with heat.
Describing a person who acts more important than they are, often with a sense of inflated ego.
Literally 'to act important'. A common way to say someone is puffing themselves up with arrogance.
彼は昇進してから偉そうにしている。
He's been puffing himself up since his promotion.
Verb meaning 'to be bossy' or 'to throw one's weight around'. Implies puffing up with pride.
あの人はいつも威張っている。
That person is always puffed up.
Idiom meaning 'to get a big head', literally 'to become a tengu'. Used when someone becomes conceited after success.
Literally 'to hang on one's nose', meaning to be proud or boastful about something.
彼は学歴を鼻にかけている。
He puffs up his academic background.
Making something expand, such as puffing up one's cheeks or inflating a balloon.
Transitive form of 膨らむ. Used for puffing out cheeks, inflating a balloon, etc.
子供が頬を膨らませた。
The child puffed up his cheeks.
風船を膨らませてください。
Please puff up the balloon.
Alternative transitive form, slightly more casual or dialectal.
Do not use physical swelling words like 膨らむ to describe a person's ego. Use phrases like 偉そうにする or 威張る instead.
彼は偉そうにしている。
He is puffed up (with arrogance).
He puffs up as soon as he gets a little praise.
He puffed up the balloon.