opening Synonyms

gap crevice initiative hole orifice possibility hatchway slot prologue start-up start starting split spiracle shoe shole sinus space slit socket stepping-stone stoma unroll unlock unlatch unlatching unfurl unfoldment uncork unbolt unbar turnstile timeliness threshold surfacing stomatous scuttle scissure prelude preliminary prefatory prefatorial precursory preamble position porthole portcullis portal porta port