noun
1.
Synonyms: beginning , birth, commencement, dawn, dawning, onset, outset, outstart, setout, start
Antonyms: closing
2.
Synonyms: aperture , hole, orifice, outlet, vent
3.
Synonyms: gap 1, breach, break, discontinuity, hole
4.
Synonyms: opportunity , break, chance, look-in, occasion, shot, show, squeak, time