Leavening

[Tina]

The act of making light, or causing to ferment, by means
of leaven.

[Justin Bieber]

When you [get to] [piss off] from work early because you hurt [your knee].

[exinilu]

A substance used in dough or batter to make it rise, such as yeast or baking powder.

[Mary Mallozziberg]

present participle of leaven