base
basement
basis
bearing wall
bed
bedding
bedrock
brace
buttress
column
floor
flooring
fond
footing
foundation
fundament
fundamental
ground
grounds
groundwork
hardpan
infrastructure
pavement
principle
prop
radical
riprap
rock bottom
root
rudiment
seat
seating
shore
sill
solid ground
solid rock
stay
stereobate
stylobate
substratum
substruction
substructure
support
terra firma
underbuilding
undercarriage
undergirding
understruction
understructure