1904, from love (n.) + seat (n.).

also lovebird, 1590s, small species of West African parrot, noted for the remarkable attention mating pairs pay to one another; figurative sense of "a lover" is attested from 1911.

Hold hands, you lovebirds. [Emil Sitka]

"courtship," mid-15c.; see love (n.) + make (v.). Phrase make love is attested from 1570s in the sense "pay amorous attention to;" as a euphemism for "have sex," it is attested from c. 1950.

"woman who is the object of one's affections," 1733; see lady + love (n.).

"child born out of wedlock, child of illicit love," 1798, from love (n.) + child. Compare German Liebeskind. Earlier was love brat (17c.).

mid-13c., from love (n.) + letter (n.).

"gentle blow given affectionately," 1848, from love (n.) + tap (n.2).

"a marked exhibition of mutual love; an interview between lovers; a pictured, written, or acted representation of such an interview" [Century Dictionary], by 1630s, from love (n.) + scene. 

old name for "tomato," 1570s, translating French pomme d'amour, corresponding to German Liebesapfel, etc., but the alleged aphrodisiac qualities that supposedly inspired the name seem far-fetched. The phrase also has been explained as a mangled transliteration of the Italian name pomo d'oro (by 1560s), taken as from adorare "to adore," but probably rather from d'or "of gold" (the earliest tomatoes brought to Italy in the mid-1500s apparently were of the yellow or orange variety), or, less likely, pomo de'Mori or Spanish pome dei Moro, literally "Moorish apple."

c. 1300, luue langing, from love (n.) + longing (n.).