rigor

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Strictness or severity, as in temperament, action, or judgment.
2. n. A harsh or trying circumstance; hardship. See Synonyms at difficulty.
3. n. A harsh or cruel act.
4. n. Medicine Shivering or trembling, as caused by a chill.
5. n. Physiology A state of rigidity in living tissues or organs that prevents response to stimuli.
6. n. Obsolete Stiffness or rigidity.

Century Dictionary and Cyclopedia

1. n. The state or property of being stiff or rigid; stiffness; rigidity; rigidness.
2. n. The property of not bending or yielding; inflexibility; stiffness; hence, strictness without allowance, latitude, or indulgence; exactingness: as, to execute a law with rigor; to criticize with rigor.
3. n. Severity of life; austerity.
4. n. Sternness; harshness; cruelty.
5. n. Sharpness; violence; asperity; inclemency: as, the rigor of winter.
6. n. That which is harsh or severe; especially, an act of injustice, oppression, or cruelty.
7. n. (rī′ gor). [NL.] In pathology, a sudden coldness, attended by shivering more or less marked, which ushers in many diseases, especially fevers and acute inflammation: commonly called chill. It is also produced by nervous disturbance or shock. [In this sense always spelled rigor.]
8. n. Synonyms and Rigor, Rigidity, Rigidness, inclemency. There is a marked tendency to use rigidity of physical stiffness. Rigidity seems to take also the passive, while rigor takes the active, of the moral senses; as, rigidity of manner, of mood; rigor in the enforcement of laws. Rigidness perhaps holds a middle position, or inclines to be synonymous with rigidity. Rigor applies also to severity of cold. See austere.

Wiktionary

1. n. US alternative spelling of rigour.
2. n. slang an abbreviated form of rigor mortis.

GNU Webster's 1913

1. n. Rigidity; stiffness.
2. n. (ed.) A sense of chilliness, with contraction of the skin; a convulsive shuddering or tremor, as in the chill preceding a fever.
3. n. The becoming stiff or rigid; the state of being rigid; rigidity; stiffness; hardness.
4. n. (Med.) See 1st Rigor, 2.
5. n. Severity of climate or season; inclemency.
6. n. Stiffness of opinion or temper; rugged sternness; hardness; relentless severity; hard-heartedness; cruelty.
7. n. Exactness without allowance, deviation, or indulgence; strictness; ; -- opposed to lenity.
8. n. Severity of life; austerity; voluntary submission to pain, abstinence, or mortification.
9. n. obsolete Violence; force; fury.

WordNet 3.0

1. n. the quality of being valid and rigorous
2. n. something hard to endure
3. n. excessive sternness