transitive. To show or express disapproval of (a person); to criticize.

intransitive. To pass judgement on a person or thing; esp. to express a harsh or unfavourable opinion of a person or thing; to find fault.

intransitive. To comment critically (on, upon), to utter criticism (usually of an adverse kind); to express censure or blame.

intransitive. More generally: to watch someone doing something and offer (unwelcome) advice or commentary.

transitive. Chiefly U.S. To disparage, belittle; to criticize. Cf. talk, v. 9a(b).