also daydream, "a reverie, pleasant and visionary fancy indulged in when awake," 1680s, from day + dream (n.). As a verb, attested from 1820. Related: Day-dreamer; day-dreaming. Daymare "feeling resembling a nightmare experienced while awake" is from 1737.

the sort of improbable fantasy one has while smoking opium, 1870, from pipe (n.1) in the smoking sense + dream (n.). Old English pipdream meant "piping," from dream in the sense of "music."

"world of dreams or illusions," 1817, from dream (n.) + world.

1560s, "full of dreams," hence "associated with dreams," from dream (n.) + -y (2). Sense of "dream-like, vague, indistinct" is by 1848. Meaning "perfect, ideal," is noted as a teen vogue word in 1941, American English teen slang. Compare dreamboat "romantically desirable person;" dream girl, etc. Related: Dreamily; dreaminess.

before vowels oneir-, word-forming element meaning "of or pertaining to a dream or dreams," from Greek oneiros "a dream," a word of uncertain origin, perhaps related to Armenian anurj, Albanian (Gheg) âdërrë.

alternative past tense and past participle of dream (v.).

"romantically desirable person," 1947, from dream (n.) + boat (n.). The phrase was in use about two decades before that. "When My Dream Boat Comes Home" was the title of a 1936 song credited to Guy Lombardo and "Dream Boat" was the title of a 1929 book.

It is rare indeed that a designer ever has the opportunity to build his dream boat. Chris Smith, all his life, had held in mind a boat of about fifty feet overall which would be the last word in yacht design and performance. [Motor Boating, December 1929]

1610s, from un- (1) "not" + past participle of dream (v.).

"of or pertaining to dreams," 1859, from Greek oneiros "a dream" (see oneiro-) + -ic.

"landscape seen in dreams," 1858, from dream (n.) + second element abstracted from landscape, etc.