名詞 motive:

1. the psychological feature that arouses an organism to action toward a desired goal; the reason for the action; that which gives purpose and direction to behavior
   同義詞：motivation, need
2. a theme that is elaborated on in a piece of music
   同義詞：motif

形容詞 motive:

1. causing or able to cause motion
   同義詞：motor
2. impelling to action
   同義詞：motivative, motivating

1. He showed his sinister motive at last.
   他終于露出了他那邪惡的用心。
2. Can we assign jealousy as the motive for the crime?
   我們能否確定這一犯罪動機是出於嫉妒?
3. The police have excluded robbery as a motive for the murder.
   警方已排除該謀殺案中有搶劫的動機。
4. Her prime motive was personal ambition.
   她的主要動機是為了實現(xiàn)個人的志向。
5. I don't understand what his motive is.
   我不知道他的動力是什么。
6. His sole motive is to make more money.
   他唯一的動機就是多賺錢。

mo.tive

n.（名詞）
An emotion, desire, physiological need, or similar impulse that acts as an incitement to action.
動機：一種能作為誘導(dǎo)物而激發(fā)行為的情緒、愿望、心理需要或者類似的心理推動力
[mô.tv, mô-tôv.] A motif in art, literature, or music.
[mô.tv, mô-tôv.] 主題：藝術(shù)、文學(xué)或者音樂的主題
adj.（形容詞）
Causing or able to cause motion:
運動的：引起運動的或能引起運動的：
例句：
motive power.
動力（電汽力等）

Impelling to action:
積極的：引發(fā)行動的：
例句：
motive pleas.
積極的請求

Of or constituting an incitement to action.
動機的：引發(fā)行動的誘導(dǎo)物的或能夠構(gòu)成誘導(dǎo)物產(chǎn)生行動的
v.tr.（及物動詞）
mo.tived,mo.tiv.ing,mo.tives
To motivate.
促使

來源：
Middle English motif, motive
中古英語 motif, motive
from Old French motif
源自 古法語 motif
from Late Latin môtovus [of motion]
源自 后期拉丁語 môtovus [運動的]
from Latin môtus [past participle of] movôre [to move] * see meu…-
源自 拉丁語 môtus [] movôre的過去分詞 [移動] *參見 meu…-