rigour

nouns

the quality of being valid and rigorous
cogency, rigor, rigour, validity
something hard to endure
"the asperity of northern winters"
asperity, grimness, hardship, rigor, rigorousness, rigour, rigourousness, severeness, severity
excessive sternness
"severity of character"; "the harshness of his punishment was inhuman"; "the rigors of boot camp"
hardness, harshness, inclemency, rigor, rigorousness, rigour, rigourousness, severeness, severity, stiffness