Synonyms of toughness

1 Syllable
thew, spunk, pluck, strength, will, grit
2 Syllables
spine, moxie, strictness, sternness, firmness, verve
3 Syllables
resolve, volition, purpose, doggedness, energies, energy, backbone, brawniness, stalwartness, steadiness, sturdiness, seriousness, solidness, earnestness, robustness, sprightliness, stubbornness, potence, fixedness, stringency, willpower
4 Syllables
obstinacy, stabilities, rigidity, resolution, stability, powerfulness, tolerance, obstinance, persistence, decidedness, rigorousness, fortitude
5 Syllables
perseverance, purposefulness, resoluteness, purposiveness, decisiveness, impliability
6 Syllables
impermeability, inelasticity