(~s)
1.
A ~ is a pipe, tube, or channel which carries a liquid or gas.
...a big air ~ in the ceiling.
N-COUNT: usu with supp
2.
A ~ is a tube in your body which carries a liquid such as tears or bile.
...tear ~s.
N-COUNT: with supp
DUCT
Meaning of DUCT in English
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012