形容詞 improper:

1. not suitable or right or appropriate
2. not conforming to legality, moral law, or social convention
   同義詞：unconventional, unlawful
3. not appropriate for a purpose or occasion
   同義詞：unsuitable, wrong

1. The machine tool went out of control because of improper use.
   由于使用不當，機床失去控制。
2. Improper, unlawful, or incorrect use; misapplication.
   錯用不正確，不合法或錯誤的使用; 誤用
3. You will make a mistake by using the improper tool.
   你用那種不恰當?shù)墓ぞ邥稿e誤。
4. Laughing and joking are considered improper behaviors at a funeral.
   在葬禮上發(fā)笑或開玩笑是失禮的行為。

im.prop.er

adj.（形容詞）
Not suited to circumstances or needs; unsuitable:
不適當?shù)模煌桩數(shù)模汉颓樾位蛐枰幌喾Q的；不合適的：
例句：
improper shoes for a walk on the beach; improper medical treatment.
不適于在海灘上散步的鞋；不適當?shù)闹委?/br>
Not in keeping with conventional mores; indecorous:
不合宜的：和傳統(tǒng)的規(guī)范不相符的；不體面的：
例句：
improper behavior.
不合宜的行為

Not consistent with established truth, fact, or rule; incorrect.
錯誤的，不正確的：與既定真相、事實或原則不一致的；錯誤的
Irregular or abnormal.
不規(guī)范的，不正常的

【引伸】
improp.erly
adv.（副詞）
improp.erness
n.（名詞）
<參考詞匯><同義詞>improper,unbecoming,unseemly,indelicate,indecent,indecorousThese adjectives mean not in keeping with accepted standards of what is right or proper.
這些形容詞的意思是和被接受的正確或合適的標準不符的。
Improper often refers to unethical conduct,a breach of etiquette, or morally offensive behavior:
Improper 經(jīng)常是指不道德的行為，對禮儀的怠慢或者無禮的舉止：
例句：
pleasant but slightly improper to dine alone with a married person.
和已婚的人一起吃飯是令人感到愉快的但卻稍微不合宜。

Unbecoming suggests what is beneath the standard implied by one`s character or position:
Unbecoming 意味著在某人的身份或地位所示的標準以下的：
例句：
language unbecoming to a gentleman. What isunseemly or indelicate is in gross violation of good taste;
和紳士身份不符的言語。 Unseemly 或者 indelicate 是指對良好品味的粗俗破壞：

indelicate especially suggests immodesty, coarseness, or tactlessness:
indelicate 尤指錯誤地使用褻瀆語；
例句：
unseemly to use profanity;
不雅的暗示；

例句：
an indelicate suggestion.
失禮的提議。

Indecent refers to what is morally offensive or harmful:
Indecent 用于道德上無禮的或有害的事：
例句：
an earthy but not indecent story.
一個庸俗但并不下流的故事：

Indecorous implies violation of the mores or manners of polite society:
Indecorous 是指對文明社會的規(guī)范和禮儀的破壞：
例句：
indecorous behavior;
不合禮節(jié)的行為；

例句：
an indecorous proposition.
不道德的要求