Is tough an adjective

Answer 1

Yes, the word 'toughness' is a noun; a word for the state of being strong enough to withstand adverse conditions or rough handling; the ability to deal with hardship or to cope in difficult situations; the quality of being difficult to cut or chew; a word for a thing.

Answer 2

yes.

for example- the task was difficult

Answer 3

yes
yes

Answer 4

Yes, it is.