Longman Dictionary of Contemporary English - bellow

~1 v 1 to shout loudly, especially in a low voice  (Tony bellowed instructions from an upstairs window.) 2 to make the deep hollow sound that a bull1 (1) makes ~2 n 1 the deep hollow sound that a bull1 (1) makes 2 bellows plural 3 a) an object that you use to blow air into a fire b) part of a musical instrument, such as an organ (2), that uses air to produce sound