understructure

cellar storage vault

bottom crypt excavation substructure

furnace room subterranean room underbuilding

attic

ground seat

basis bedrock bottom groundwork rest substratum

foothold

basement bedrock bottom establishment foot ground groundwork infrastructure installation seat seating settlement substratum substructure underpinning warrant

resting place

top

authority base bedrock groundwork infrastructure support

ABCs basics bed bottom foot footing ground guts heart justification nitty-gritty nub prop reason root setup stay substratum substructure

bottom line brass tacks nuts and bolts underpinning

cowardice exterior exteriority fear outside top

base basis bed bottom foot footing ground groundwork support

underpinning

top

preparation

ABCs background base bedrock cornerstone footing foundation ground infrastructure origin preliminaries root substratum

underpinning