long underwear
US /ˌlɔŋ ˈʌndərwer/
UK /ˌlɔŋ ˈʌndərwer/

1.
ondergoed, thermo-ondergoed
a two-piece garment, typically made of cotton or wool, worn under other clothes for warmth, covering the body from the neck to the ankles and wrists.
:
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He put on his long underwear before heading out into the snow.
Hij trok zijn ondergoed aan voordat hij de sneeuw in ging.
•
For cold weather, long underwear is essential.
Voor koud weer is ondergoed essentieel.