- sleep (v.)
- O.E. slępan "to sleep" (class VII strong verb; past tense slep, pp. slępen), from W.Gmc. *slępanan (cf. O.S. slapan, O.Fris. slepa, M.Du. slapen, Du. slapen, O.H.G. slafen, Ger. schlafen, Goth. slepan "to sleep"), from PIE base *sleb- "to be weak, sleep" (cf. O.C.S. slabu, Lith. silpnas "weak"), which is perhaps connected to the root of slack (adj.). Sleep with "do the sex act with" is in O.E.
"Gif hwa fęmnan beswice unbeweddode, and hire mid slępe ..." [Laws of King Alfred, c.900]
Sleep around first attested 1928. Sleeping sickness as a specific African tropical disease is first recorded 1875. Sleepless is from early 15c.; sleepy first attested early 13c. - sleep (n.)
- O.E. slęp from the root of sleep (v.) (cf. cognate O.S. slap, O.Fris. slep, M.Du. slęp, Du. slaap, O.H.G. slaf, Ger. Schlaf, Goth. sleps). Personified as L. Somnus, Gk. Hypnos (see somnolence). Fig. use for "repose of death" was in O.E.; to put (an animal) to sleep "kill painlessly" is recorded from 1942. Sleep-walker "somnambulist" is attested from 1747. To be able to do something in (one's) sleep "easily" is recorded from 1953.