1.
Inclined to judge severely and find fault.
2.
Characterized by careful, exact evaluation and judgment: a critical reading.
3.
Of, relating to, or characteristic of critics or criticism: critical acclaim; a critical analysis of Melville's writings.
4.
Forming or having the nature of a turning point; crucial or decisive: a critical point in the campaign.
5.
a. Of or relating to a medical crisis: an illness at the critical stage. b. Being or relating to a grave physical condition especially of a patient.
6. Indispensable; essential: a critical element of the plan; a second income that is critical to the family's well-being.
7. Being in or verging on a state of crisis or emergency: a critical shortage of food.
8. Fraught with danger or risk; perilous.
9. Mathematics. Of or relating to a point at which a curve has a maximum, minimum, or point of inflection.
10. Chemistry & Physics. Of or relating to the value of a measurement, such as temperature, at which an abrupt change in a quality, property, or state occurs: A critical temperature of water is 100C, its boiling point at standard atmospheric pressure.
11. Physics. Capable of sustaining a nuclear chain reaction.