CRITICAL
critical
Noun
Adjective
- Inclined to find fault or criticize; fastidious; captious; censorious; exacting.
- Pertaining to, or indicating, a crisis or turning point.
- Extremely important.
- Relating to criticism or careful analysis, such as literary or film criticism.
- Of a patient condition involving unstable vital signs and a prognosis that predicts the condition could worsen; or, a patient condition that requires urgent treatment in an intensive care or critical care medical facility.
- Likely to go out of control if disturbed, that is, opposite of stable.
- Of the point (in temperature, reagent concentration etc.) where a nuclear or chemical reaction becomes self-sustaining.
The above text is a snippet from Wiktionary: critical
and as such is available under the Creative Commons Attribution/Share-Alike License.