(idiomatic) To not commit to a decision, to keep various options available.

(dated) A person who operates a radio transmitter on a ship or in an outpost, military unit, etc., in order to communicate over long distances.

(topology) Informally, a set such that the target point of a movement by a small amount in any direction from any point in the set is still in the set; exemplified by a full circle without its boundary.

plural of multiplicative operation

partially open; ajar / (mathematics) (referring to an interval on the real line) containing only one of its endpoints

plural of operating expense

A ceremony to mark the official opening of a building or event.

A problem with an easy solution.

Alternative spelling of bottle opener

A marsupial found in Central and South America, Chironectes minimus