improper
/ɪmˈprɒpə(r)/adjective
1- not in accordance with accepted rules or standards, especially of morality or honesty（尤指道德或诚信方面）不合标准的; 不正当的, 不得体的, 不恰当的：
he was accused of improper behaviour in his business dealings
他被指责在交易中有不正当行为
it is improper to end a sentence with a preposition.
以介词结束句子是不恰当的。
1.1
- lacking in modesty or decency不谦虚的; 不庄重的, 不体面的：
it was thought improper for elderly women to wear bright colours.
人们认为老年妇女穿着艳丽有失庄重。
派生词
improperly
adverb词源
late Middle English: from French impropre or Latin improprius, from in- 'not' + proprius 'one's own， proper'.