Definition of: tough

(tuf) adjective
1. Susceptible of great tension or strain without breaking; also, of a close texture.
2. Not easily separated; tenacious; viscid; ropy.
3. Possessing great physical endurance: a tough constitution.
4. Possessing moral or intellectual endurance; steadfast; persistent; also, stubborn.
5. Irreclaimably vicious; disreputable; vulgar.
6. Difficult to accomplish; laborious; also, severe.
7. Hard to believe; incredible.
—noun A lawless person; a rowdy; ruffian. [OE tōh]
—tough′·ly adverb
—tough′ness noun