bellows
US /ˈbel.oʊz/
UK /ˈbel.oʊz/

1.
a device with an air bag that can be squeezed together to blow air through a narrow opening, used for making a fire burn more fiercely or for playing some musical instruments
:
•
He used the bellows to fan the flames of the dying fire.
•
The blacksmith worked the metal, pumping the bellows to keep the forge hot.