dream

dream (n.) mid-13c. in the sense "sequence of sensations passing through a sleeping person's mind" (also as a verb), probably related to O.N. draumr, Dan. drèm, Swed. dröm, O.S. drom "merriment, noise," O.Fris. dram "dream," Du. droom, O.H.G. troum, Ger. traum "dream," perhaps from W.Gmc. *draugmas "deception, illusion, phantasm" (Cf. O.S. bidriogan, O.H.G. triogan, Ger. trügen "to deceive, delude," O.N. draugr "ghost, apparition"). Possible cognates outside Germanic are Skt. druh- "seek to harm, injure," Avestan druz- "lie, deceive." But O.E. dream meant only "joy, mirth," also "music." Words for "sleeping vision" in O.E. were mæting and swefn (from PIE *swep-no-; Cf. Gk. hypnos).

Much study has failed to prove that O.E. dream "noisy merriment" is the root of the modern word for "sleeping vision," despite being identical in spelling. Either the meaning of the word changed dramatically or "vision" was an unrecorded secondary O.E. meaning of dream, or there are two separate words here. "It seems as if the presence of dream 'joy, mirth, music,' had caused dream 'dream' to be avoided, at least in literature, and swefn, lit. 'sleep,' to be substituted" [OED]. Dream in the sense of "ideal or aspiration" is from 1931, from earlier sense of "something of dream-like beauty or charm" (1888). As a verb, in the current sense, from c.1200 (O.E. dremen meant "rejoice, play music"). Related: Dreamed; dreaming.