Lullaby

1. (n.) A song to quiet babes or lull them to sleep; that which quiets.

2. (v. t.) Hence: Good night; good-by.

Thesaurus Entries

Schlummerlied, Wiegenlied, anesthetic, berceuse, cradlesong, hypnotic, mandrake, morphia, morphine, nightcap, opiate, opium, poppy, sedative, sleep-bringer, sleep-inducer, sleep-producer, somnifacient, soporific