critical

/ˈkrɪdəkəl/

/ˈkrɪtɪkʊl/

The adjective critical has several meanings, among them, "vital," "verging on emergency," "tending to point out errors," and "careful."

If you're an emergency-room doctor with a patient in critical condition (on the highest alert), it's absolutely critical (vital or essential) that you be critical (careful and judicious) in your approach to their care, so that at the critical (decisive) moment, you can save their life. You must also be critical (that is, you must point out all the errors and flaws) of the jobs your colleagues are doing.

Definitions of critical

1. adjective

   of or involving or characteristic of critics or criticism
   “critical acclaim”
2. adjective

   characterized by careful evaluation and judgment
   “a critical reading”

   “a critical dissertation”

   “a critical analysis of Melville's writings”

   synonyms:

   appraising, evaluative

   exercising or involving careful evaluations

   discriminative, judicial

   expressing careful judgment

   discerning

   having or revealing keen insight and good judgment

   scholarly

   characteristic of scholars or scholarship

   antonyms:

   uncritical

   marked by disregard for critical standards or procedures

   unscholarly

   not scholarly
3. adjective

   marked by a tendency to find and call attention to errors and flaws
   “a critical attitude”

   synonyms:

   captious, faultfinding

   tending to find and call attention to faults

   censorious

   harshly critical or expressing censure

   deprecative

   given to expressing disapproval

   hypercritical, overcritical

   inclined to judge too severely

   searing

   severely critical

   scalding, scathing, vituperative

   marked by harshly abusive criticism

   unfavorable, unfavourable

   not encouraging or approving or pleasing

   sarcastic

   expressing or expressive of ridicule that wounds

   antonyms:

   uncritical

   not critical; not tending to find or call attention to errors
4. adjective

   urgently needed; absolutely necessary
   “a critical element of the plan”

   “critical medical supplies”

   synonyms: vital

   indispensable

   not to be dispensed with; essential
5. adjective

   forming or having the nature of a turning point or crisis
   “a critical point in the campaign”

   “the critical test”

   synonyms: decisive

   crucial, important

   of extreme importance; vital to the resolution of a crisis
6. adjective

   being in or verging on a state of crisis or emergency
   “a critical shortage of food”

   “a critical illness”

   “an illness at the critical stage”

   synonyms:

   acute

   of critical importance and consequence

   dangerous, grave, grievous, life-threatening, serious, severe

   causing fear or anxiety by threatening great harm

   desperate, dire

   fraught with extreme danger; nearly hopeless

   crucial, important

   of extreme importance; vital to the resolution of a crisis

   antonyms:

   noncritical

   not in a state of crisis or emergency

   acritical

   without a crisis (as of some diseases)
7. adjective

   at or of a point at which a property or phenomenon suffers an abrupt change especially having enough mass to sustain a chain reaction
   “a critical temperature of water is 100 degrees C--its boiling point at standard atmospheric pressure”

   “critical mass”

   “go critical”

   synonyms:

   supercritical

   (especially of fissionable material) able to sustain a chain reaction in such a manner that the rate of reaction increases

   antonyms:

   noncritical

   not critical; not at a point of abrupt change