Opening

To make something accessible or allow for passage by moving from a shut position.

"Turn the doorknob to open the door."

To make (an open space, etc.) by clearing away an obstacle or obstacles, in order to allow for passage, access, or visibility.

"He opened a path through the undergrowth."

To bring up, broach.

"I don't want to open that subject."

To enter upon, begin.

"to open a case in court, or a meeting"

An act or instance of making or becoming open.

"He remembered fondly the Christmas morning opening of presents."

Something that is open.

"A salamander darted out of an opening in the rocks."

An act or instance of beginning.

"Their opening of the concert with Brass in Pocket always fires up the crowd."

Something that is a beginning.

Pertaining to the start or beginning of a series of events.

"The opening theme of Beethoven's Fifth Symphony is, perhaps, the most recognizable in all of European art music."

Describing the first period of play, usually up to the fall of the first wicket; describing a batsman who opens the innings or a bowler who opens the attack