- near, as to a common center; adjacent, especially to a city: The city is enveloping its close-in suburbs.
- occurring or provided at close quarters: Fighter planes provided daring close-in air support.
- (of days) to become shorter with the approach of winter
- (foll by on or upon) to advance (on) so as to encircle or surround
Idioms and Phrases with close in
Surround, enclose, envelop, as in The fog closed in and we couldn't see two yards in front of us, or She felt the room was closing in. [c. 1400]
Also, close in on or upon. Draw in, approach, as in The police closed in on the suspect. [Early 1800s]