Undersuit n. : A suit worn under another suit; a suit of underclothes.

Example:
What would be a Good Undersuit for a Halloween Costume?

Taxonomy
Undersuit, free encyclopedia, search, garment, Personal tools, Interaction, Toolbox, non-profit organization, occupation, drysuit, spacesuit, job, en.wikipedia, wiki, Diving equipment, Space exploration, Underwater diving, Articles lacking sources.

Defination from the web:
Undersuit. From Wikipedia, the free encyclopedia. Jump to: navigation, search. An undersuit is a garment worn under a diver's drysuit or under a spacesuit. ... Retrieved from "http://en.wikipedia.org/wiki/Undersuit" Categories: Diving equipment | Space exploration | Occupation stubs ...