(transitive, intransitive) Used other than figuratively or idiomatically: see break, open. / To make a breakthrough on a mystery or problem; to cause a breakthrough to be made.

Any system that does not use feedback

the state or quality of being open-ended

(informal, computing) A programmer who works only on open source programs.

Third-person singular simple present indicative form of break open

Third-person singular simple present indicative form of lay open

to expand, to widen, to unwrap or unfold, to spread out from a compact state

(rare, mathematics, of a set) Being the interior of its closure.

plural of open water

(religion) The practice of some Protestant churches to allow all people to take Communion, regardless of being members of the church or not.