opening (n.)

Old English openung "act of making open" (a door, mouth, etc.), "disclosure, manifestation," verbal noun from present participle of open (v.). Meaning "vacant space, hole, aperture, doorway" is attested from c. 1200. Meaning "act of opening (a place, to the public)" is from late 14c.  Sense of "opportunity, chance" is from 1793. Sense of "action of beginning (something)" is from 1712; meaning "first performance of a play" is 1855; that of "start of an art exhibit" is from 1905. Opening night is attested from 1814.