An "AERATOR" is the part on the end of your faucet that the water comes out from. It usually holds a screen and water saver in place.
A fish AERATOR is a device used to add oxygen into a fish tank so that the fish do not suffocate as they consume the increasingly depleted oxygen supply
The break and repair events probably released debris into the pipe. These eventually get caught in the faucet valve and it may have to be disassembled to remove them. check the areator