This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

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n. An overnight.

n. One making an overnight stay or trip.

n. Something relating to or used for overnight travel.

n. A person who overnights, or stays overnight.

n. Something that serves overnight travel, such as a night train.

n. A stay or event that takes place overnight.

n. a guest who stays overnight

n. a small traveling bag to carry clothing and accessories for staying overnight

"You didn't complain about the rest area overnighter or having to put up with a visit to my in-laws."

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