Looking for a good football definition of a "loaf"

A loaf is committed any time someone is not hustling and finishing a play to the whistle. Examples:

Defender on other side of the field not getting into his pursuit lane.

WR not exploding off the line on a running play

QB not carrying out his boot fake after the hand off


There's dozens of examples one could think of. Basically you are looking for someone who is not carrying out their responsibility.