a.

1. 不適當的，不相稱的；不得體的[（+to）]
   an unbecoming speech

   有失體面的話

   Such thoughts are unbecoming to you.

   這些想法與你的身分不相稱。

2. （服飾等）不合身的；不相配的[（+to）]
   The colours are unbecoming to her complexion.

   這些顏色與她的膚色不相配。

   an unbecoming garment

   不合身的衣服

adj.

1. (especially of clothing) not flattering.
2. (of behaviour) not fitting; unseemly.