the odd one out

US /ðɪ ˌɑːd wʌn ˈaʊt/
UK /ðɪ ˌɑːd wʌn ˈaʊt/
"the odd one out" picture
1.

異類, 例外, 與眾不同的人

a person or thing that is different from or excluded from others in a group or series

:
In this group of fruits, the apple is the odd one out because all the others are berries.
在這組水果中,蘋果是異類,因為所有其他都是漿果。
He always felt like the odd one out in his family because he was the only artist.
他總覺得自己是家裡的異類,因為他是唯一的藝術家。