Q:

What is the meaning of “ ヒキョーだ”? What would be a good english word/phrase to replace it?

I am translating a manga and this is a word that I could not find a translation for. If someone could help it would be greatly appreciated!!
In the manga, there isnt really a sentence but the context is that one person just threatened the boy in order to get him to help them & The boy said “ヒキョーだ”
the manga screenshot!

A:

That is 「卑怯{ひきょう}」 written in katakana.
「卑怯だ！」 means "You/He/They are/is a coward!", "That's unfair!", "That's so mean!", etc.
Without context, I could not tell you which one would fit best.

