motive
n.
mid-14c., "something brought forward," from Old French motif "will, drive, motivation," noun use of adjective, literally "moving," from Medieval Latin motivus "moving, impelling," from Latin motus "a moving, motion," past participle of movere "to move" (see move, v.). Meaning "that which inwardly moves a person to behave a certain way" is from early 15c.
adj.
late 14c., from Old French motif "moving" or directly from Medieval Latin motivus "moving, impelling," from past participle stem of movere "to move" (see move, v.).
〔蒋〕[mot动，-ive形容词后缀，…的] 发动的，运动的;[转为名词] 动机
〔李〕[mot=to move运动；-ive a.=able to能……的→“able to move能使运动的”→]Ⅰa. causing movement发动的，运动的