crit·i·cal / ˈkritikəl/ • adj. 1. expressing adverse or disapproving comments or judgments.2. expressing or involving an analysis of the merits and faults of a work of literature, music, or art: she never won the critical acclaim she sought. ∎  (of a published literary or musical text) incorporating a detailed and scholarly analysis and commentary: a critical edition of a Bach sonata.3. (of a situation or problem) having the potential to become disastrous; at a point of crisis. ∎  (of a person) extremely ill and at risk of death: he had been in critical condition since undergoing surgery. ∎  having a decisive or crucial importance in the success or failure of something: temperature is a critical factor in successful fruit storage..4. Math. & Physics relating to or denoting a point of transition from one state to another. ∎  (of a nuclear reactor or fuel) maintaining a self-sustaining chain reaction: the reactor is due to go critical in October.DERIVATIVES: crit·i·cal·i·ty / ˌkritəˈkalitē/ n. (in senses 3 and 4).crit·i·cal·ly / ˈkritik(ə)lē/ adv. he's critically ill. crit·i·cal·ness n.

critical critical mass originally, the minimum amount of fissile material needed to maintain a nuclear chain reaction. In extended usage, the minimum size or amount of resources required to start or maintain a venture.
critical path the sequence of stages determining the minimum time needed for an operation, especially when analysed on a computer for a large organization.