Low space beneath a floor of a building

Usage examples of crawlspace.

Sundered metal shrieked in protest in the crawlspace beneath the control room, and the periscopes rattled within their housings.

Narrow crawlspaces and vertical cracks also showed signs of passage: a delicate crystal crushed here, a smear on an otherwise snowy white dripstone there—the variety of ways a human could betray his movements through a cave were almost infinite.

They were full of talk about how there was coin and silverware and jewelry and strange golden artifacts hidden all in the walls and crawlspaces of the house, or under the privy, or even buried in the ground, though it would take six kinds of fool to try to bury anything in Barcy, the land being so low and wet that anything buried in it was likely to drift away in underground currents or bob to the surface like the corpse of a drowned man.

They were not much better than urchins, living in corridors and crawlspaces instead of streets and alleys, a whole subculture that existed, but no one looked at too closely.

The invading armies of the Yuuzhan Vong had flushed all manner of vermin from them, including entire cultures that had existed in the crawlspaces of the original inhabitants' government.

Jacob, too, comes forth from the dark crawlspace under the porch, having watched in terror from behind the latticework skirt.