toughness

adjective

1. strong but pliant; that will bend, twist, etc. without tearing or breaking
2. that will not cut or chew easily: tough steak
3. strongly cohesive; glutinous; viscous; sticky: tough putty
4. 1. strong of physique; robust; hardy
   2. displaying mental or moral firmness
5. hard to convince or influence; stubborn
6. practical and realistic rather than emotional or sentimental
7. overly aggressive; brutal or rough
8. 1. very difficult; toilsome
   2. vigorous or violent: a tough fight
9. Informal unfavorable; bad: a tough break
10. ☆ Slang fine; excellent: a generalized term of approval

noun