toughness vs legs

toughness and legs both are nouns.

Word	Noun	Adjective	Verb	Adverb
toughness	Yes	No	No	No
legs	Yes	No	No	No

As nouns, legs is a hyponym of toughness; that is, legs is a word with a more specific, narrower meaning than toughness:

toughness (noun)	legs (noun)
the property of being big and strong	staying power
enduring strength and energy
impressive difficulty
the elasticity and hardness of a metal object; its ability to absorb considerable energy before cracking