How to say "chicken-hearted" in Japanese

• チキンハート
  na-adjective, nounA direct loanword for the cowardly, easily frightened sense of 'chicken-hearted'. It matches the English image closely, but as an uncommon word it is seldom the expression learners actually need when translating this idea.
• ケツの穴が小さいけつのあながちいさい
  expression, prenominal modifierA vulgar idiom, literally 'the hole of one's backside is small', covering the cowardly sense with a strong nuance of pettiness. Its crudeness makes it unsuitable for polite contexts, and it is uncommon besides.

Both are uncommon ways to render 'chicken-hearted': 「チキンハート」 is a straightforward loanword for the cowardly sense, while 「ケツの穴が小さい」 is a vulgar idiom stressing small-mindedness, best avoided in polite contexts.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• チキンハートchicken-hearted
• ケツの穴が小さいけつのあながちいさいsmall-minded