Open English Wordnet
Nouns
(n)motivation, motive, needthe 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“we did not understand his motivation”, “he acted with the best of motives”
Adjectives
(s)motivative, motive, motivatingimpelling to action“it may well be that ethical language has primarily a motivative function” (Arthur Pap), “motive pleas”, “motivating arguments”