WordNet sense 1 (a public official authorized to decide questions brought before a court of justice):

jurist, justice, magistrate

WordNet sense 2 (an authority who is able to estimate worth or quality):

evaluator

WordNet sense 3 (put on trial or hear a case and sit as the judge at the trial of):

adjudicate, try

WordNet sense 4 (pronounce judgment on):

label, pronounce

WordNet sense 5 (judge tentatively or form an estimate of (quantities or time)):

estimate, gauge, guess, approximate, approximate, estimate

WordNet sense 6 (form a critical opinion of):

evaluate, pass judgment