plural of letter opener

(UK regional) The medlar fruit.

plural of open house

plural of open day

(travel, aviation) A fare construction where the destination is not the same as the origin point for the return, or where the origin differs from the return destination.

plural of open wound

the outside / the outdoors; a space not surrounded by walls; an open space

A casual event where an institution is open for inspection by anyone interested.

(clothing) Open at the neck.

(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.