Noah Webster's New International Dictionary of the English Language

1. (n.) Qualified to criticize, or pass judgment upon, literary or artistic productions.

2. (n.) Pertaining to criticism or the critic's art; of the nature of a criticism; accurate; as, critical knowledge; a critical dissertation.

3. (n.) Inclined to make nice distinctions, or to exercise careful judgment and selection; exact; nicely judicious.

4. (n.) Inclined to criticize or find fault; fastidious; captious; censorious; exacting.

5. (n.) Characterized by thoroughness and a reference to principles, as becomes a critic; as, a critical analysis of a subject.

6. (n.) Pertaining to, or indicating, a crisis, turning point, or specially important juncture; important as regards consequences; hence, of doubtful issue; attended with risk; dangerous; as, the critical stage of a fever; a critical situation.