molecular cloud

[ muh-lek-yuh-ler kloud ]

noun

, Astronomy.

1. an interstellar cloud of gas and dust composed of hydrogen, helium, and other molecular remnants of a supernova. star formation ( def 1 ), stellar nursery ( def ).

molecular cloud

noun

1. a cool dense interstellar region composed of a wide variety of molecules, mainly hydrogen, plus some dust, in which stars are forming

Word History and Origins

Origin of molecular cloud¹

First recorded in 1970–75