[open.ing] n (13c) 1 a: an act or instance of making or becoming open b: an act or instance of beginning: commencement; esp: a formal and usu. public event by which something new is put officially into operation
2: something that is open: as a (1): breach, aperture (2): an open width: span b: an area without trees or with scattered usu. mature trees that occurs as a break in a forest c: two pages that face one another in a book
3: something that constitutes a beginning: as a: a planned series of moves made at the beginning of a game of chess or checkers--compare endgame, middle game b: a first performance
4. a: occasion, chance b: an opportunity for employment