1) Access to plumbing or wiring 2) Australian indie rock group 3) Crawl space 4) Space 
The area within the confines of the foundation and between the ground and the underside of the lowest floor structural component. 
[n] - low space beneath a floor of a building
crawl space noun low space beneath a floor of a building; gives workers access to wiring or plumbing
The unoccupied, and usually unfinished and unconditioned space between the floor, foundation walls, and the slab or ground of a building.
(in a building) an area accessible by crawling, having a clearance less than human height, for access to plumbing or wiring, storage, etc.