plural of closed file

(chess) A file with pawns of both colors on it.

(topology) A map from the circle, S¹, to a topological space.^((McLarty, p. 4))

(logic) A formula which has no free occurrences of variables; or equivalently, in which all occurrences of variables are bound.

A relatively small closed city

Any of several settlements in Russia that have travel and residency restrictions

A fixed period during which killing game or catching certain fish is prohibited by law.

Hotly contested; won or achieved only by a small margin.

(nautical) Sailing close to the wind

The characteristic or state of being close-minded.