Webster 1913 Edition
The quality or state of being tough.
Webster 1828 Edition
1.Viscosity; tenacity; clamminess; glutinousness; as the toughness of mucus.
2.Firmness; strength of constitution or texture.
toughness (plural toughnesses)
- (uncountable) The state of being tough
- (physics, of a metal) Resistance to fracture when stressed
- A formidable difficulty