Erotic, amatory, amorous, amative, aphrodisiac all involve the idea of love for the opposite sex, but they are not freely interchangeable because of differences in denotation as well as in implications.
Erotic, though the strongest in its suggestions of love as a violent passion or as a physical appetite, is rarely applied to persons as distinct from their behavior, reactions, or emotions, and it is especially used in characterizing or classifying emotions, motives, or themes in art.
Amatory is a synonym of erotic but weaker in its suggestion of sexual desire; it sometimes connotes little more than ardent admiration; thus, one might more correctly describe the youthful love poems of Tennyson as amatory than as erotic poetry.
Amorous is applied chiefly to persons, their words, or their acts especially when they are falling in love or making love. The word often suggests ripeness or eagerness for love. In this sense it is also applied, chiefly in poetry, to animals.
Amative implies merely a disposition to fall in love or a propensity for loving; it is chiefly used in describing temperaments or in analyzing character.
Aphrodisiac is applied to things (as drugs or writings) that arouse or tend to arouse sexual desire.