se·vere 
(sə-vîr)
(sə-vîr)adj. se·ver·er, se·ver·est
1. Unsparing, harsh, or strict, as in treatment of others: a severe critic.
2. Marked by or requiring strict adherence to rigorous standards or high principles: a severe code of behavior.
3. Stern or forbidding, as in manner or appearance: spoke in a severe voice.
4. Extremely plain in substance or style: a severe black dress.
5. Causing great discomfort, damage, or distress: a severe pain; a severe storm.
6. Very dangerous or harmful; grave or grievous: severe mental illness.
7. Extremely difficult to perform or endure; trying: a severe test of our loyalty.
[Latin sevērus, serious, strict; see segh- in the Appendix of Indo-European roots.]
se·verely adv.
se·vereness n.
Synonyms: severe, stern1, austere, ascetic, strict
These adjectives mean unsparing and exacting with respect to discipline or control. Severe implies adherence to rigorous standards or high principles and often suggests harshness: "Praise or blame has but a momentary effect on the man whose love of beauty in the abstract makes him a severe critic on his own works" (John Keats).
Stern suggests unyielding disposition, uncompromising resolution, or forbidding appearance or nature: "She was a stern woman who ran the household with precision and an iron hand" (Margaret Truman).
Austere connotes aloofness or lack of feeling or sympathy, and often rigid morality: "The captain ... was an austere man that never laughed or smiled that one could see" (Alan Paton).
Ascetic suggests self-discipline and often renunciation of worldly pleasures for spiritual improvement: "Be systematically ascetic ... do ... something for no other reason than that you would rather not do it" (William James).
Strict means requiring or showing stringent observance of obligations, rules, or standards: "She was afraid to wake him up because even in his sleep he seemed to be such a strict man" (Eudora Welty).
These adjectives mean unsparing and exacting with respect to discipline or control. Severe implies adherence to rigorous standards or high principles and often suggests harshness: "Praise or blame has but a momentary effect on the man whose love of beauty in the abstract makes him a severe critic on his own works" (John Keats).
Stern suggests unyielding disposition, uncompromising resolution, or forbidding appearance or nature: "She was a stern woman who ran the household with precision and an iron hand" (Margaret Truman).
Austere connotes aloofness or lack of feeling or sympathy, and often rigid morality: "The captain ... was an austere man that never laughed or smiled that one could see" (Alan Paton).
Ascetic suggests self-discipline and often renunciation of worldly pleasures for spiritual improvement: "Be systematically ascetic ... do ... something for no other reason than that you would rather not do it" (William James).
Strict means requiring or showing stringent observance of obligations, rules, or standards: "She was afraid to wake him up because even in his sleep he seemed to be such a strict man" (Eudora Welty).