The Collaborative International Dictionary
Underbuilding
Underbuilding \Un"der*build`ing\, n. Same as Substruction.
Wiktionary
underbuilding
n. A substructure; foundation; infrastructure.
Usage examples of "underbuilding".
He conducted Forrester through underbuilding mazes and footbridges Forrester had not even seen, his mouth going all the while.
Forrester took five dollars from a pretty girl in a sort of mirror-bright bikini, then fifty from a man who had brought his pet animal—it was a little silk-furred monkey—down to the underbuilding park to run free, and who seemed to accept Forrester’s touch as a form of rent for the use of the premises.