deep space

WordReference Random House Learner's Dictionary of American English © 2026

ˈdeep ˈspace, n. [uncountable]

1. Aerospace, Astronomy space beyond the solar system. Also called outer space. 

WordReference Random House Unabridged Dictionary of American English © 2026

deep′ space′, 

1. Aerospace, Astronomy space beyond the limits of the solar system. Also called outer space. 

• 1950–55

deep′-space′, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

deep space noun

1. any region of outer space beyond the system of the earth and moon