If you describe things such as clothes as unbecoming, you mean that they look unattractive.
例句
...the unbecoming dress hurriedly stitched from cheap cloth.用廉价布料匆匆缝制的难看的连衣裙
ADJ-GRADED
不得体的;不合宜的;不恰当的
If you describe a person's behaviour or remarks as unbecoming, you mean that they are shocking and unsuitable for that person.
例句
His conduct was totally unbecoming to an officer in the British armed services...作为一名英军军官,他的行为极不得体。Those involved had performed acts unbecoming of university students.那些参与者的所作所为有失大学生的体面。
英英词典释义
Adjective
1. considered inappropriate for or unattractive on a particular person;
"an unbecoming style"
2. not in keeping with accepted standards of what is right or proper in polite society;
"was buried with indecent haste""indecorous behavior""language unbecoming to a lady""unseemly to use profanity""moved to curb their untoward ribaldry"