In American and Canadian English, timeout is one word in sports-related contexts, where it means an official pause in the action. Timeouts is its plural. In all other uses, time out is a two-word noun phrase.
In British English, the one-word timeout is considered incorrect. Time out is preferred, even in sports.
Examples
For example, here are a few appropriate instances of the one-word timeout in North American publications:
The Mavericks called a timeout and when Terry got to the bench, Barea was yelling at him. [Dallas Morning News]
Chris Wilcox appeared to receive most of his wrath during the timeout … [Globe and Mail]
Instead of calling an expected timeout to set up a play, Montclair Kimberley coach Paul Edwards allowed his kids to see it through without intervention. [The Star-Ledger]
And these writers demonstrate some uses where the two-word time out is more appropriate:
He’d taken time out of a recruiting trip to Houston to stop by her office … [Houston Chronicle]
Think of the difficulty involved in catching a giant tarpon on light tackle your first time out … [Miami Herald]
This time out, he splits the difference and, consequently, gives the middle of the road an interesting sheen … [Globe and Mail]
Again, the timeout–time out distinction is a nonissue British English, where time out is always preferred over timeout. The same is generally true in Australian English, although timeout appears some of the time.
