- stamina, staying power, toughness - enduring strength and energy
--1 is a kind of endurance
--1 has particulars: legs - huskiness, ruggedness, toughness - the property of being big and strong
--2 is a kind of strength
- temper, toughness - the elasticity and hardness of a metal object; its ability to absorb considerable energy before cracking
--3 is a kind of elasticity, snap
- formidability, toughness - impressive difficulty
--4 is a kind of difficulty, difficultness