WordNet sense 1 ((comparative and superlative of `early') more early than; most early):

earliest

WordNet sense 2 (at or near the beginning of a period of time or course of events or before the usual or expected time):

early

WordNet sense 3 (comparatives of `soon' or `early'):

sooner

WordNet sense 4 (before now):

originally, in the first place, in the beginning, to begin with

WordNet sense 5 (earlier in time; previously):

before