Definition of "long underwear" []

• An undergarment with shirt and drawers in one piece (noun)

WordNet. Princeton University. 2010.

• "A netlike long underwear worn under a spacesuit and that holds a maze of small tubes that circulate chilled water to prevent spacewalkers from overheating."
• "When we handed in our gear, we thanked the Army for the long underwear and stocking caps; even unworn they were nonreturnable items."