An obstacle, barrier, or bulwark.
A barrier constructed across a road, especially as a military defence
A place of confrontation.
to close or block a road etc., using a barricade
to keep someone in (or out), using a blockade, especially ships in a port
A gap permitting passage through.
The first few measures of a musical composition.
The first performance of a show or play by a particular troupe.
The initial period when a show at an art gallery or museum is first opened, especially the first evening.
A vacant position, especially in an array.
An unoccupied employment position.
In mathematical morphology, the dilation of the erosion of a set.
An act or instance of making or becoming open.
A time available in a schedule.
An opportunity, as in a competitive activity.
An act or instance of beginning.
The first few moves in a game.
Pertaining to the start or beginning of a series of events.
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