noun

1. a becoming open or causing to be open
2. an open place or part; hole; gap; aperture
3. ☆ a clearing in the midst of a wooded area
4. 1. a beginning; first part; commencement
   2. start of operations; formal beginning
   3. a first performance, as of a play
5. a favorable chance or occasion; opportunity
6. an unfilled position or office for which a person is wanted
7. Chess, Checkers the series of moves at the beginning of a game, often a specific, conventional sequence of moves

Etymology: ME openyng

adjective