Impudent.
Having rugged physical strength; inured to fatigue or hardships.
Able to survive adverse growing conditions.
Brave and resolute.
Anything, especially a plant, that is hardy.
A blacksmith's fuller or chisel, having a square shank for insertion into a square hole in an anvil, called the hardy hole.
Difficult to accept; unpalatable.
Difficult or impossible to digest.
Anything that is difficult to digest.