Old English lufu "love, affection, friendliness," from Proto-Germanic *lubo (cf. Old High German liubi "joy," German Liebe "love;" Old Norse, Old Frisian, Dutch lof; German Lob "praise;" Old Saxon liof, Old Frisian liaf, Dutch lief, Old High German liob, German lieb, Gothic liufs "dear, beloved").
The Germanic words are from PIE *leubh- "to care, desire, love" (cf. Latin lubet, later libet "pleases;" Sanskrit lubhyati "desires;" Old Church Slavonic l'ubu "dear, beloved;" Lithuanian liaupse "song of praise").
Meaning "a beloved person" is from early 13c. The sense "no score" (in tennis, etc.) is 1742, from the notion of "playing for love," i.e. "for nothing" (1670s). Phrase for love or money "for anything" is attested from 1580s. Love seat is from 1904. Love-letter is attested from mid-13c.; love-song from early 14c. To fall in love is attested from early 15c. To be in love with (someone) is from c.1500. To make love is from 1570s in the sense "pay amorous attention to;" as a euphemism for "have sex," it is attested from c.1950. Love life "one's collective amorous activities" is from 1919, originally a term in psychological jargon. Love affair is from 1590s. The phrase no love lost (between two people) is ambiguous and was used 17c. in reference to two who love each other well (c.1640) as well as two who have no love for each other (1620s).