The word ‘double date’ is an open compound noun used as a synonym for ‘infidelity’, ‘cheating’ or ‘dating two people’ by some speakers. However, this is not correct.
A double date is a situation where two couples go out on a date to see a movie, go to a restaurant, etc. It simply means an occasion where a couple goes on a date with another couple—four people in all.
Examples:
- Tomi and Charles are coming over to the restaurant, so it’s a double date.
- For most of them, a double date is romantic until it’s time to pay the bill.
The verb form is double-date.
Example:
- We’ve all been together for over a decade; we’ve even been double-dating since high school.
According to etymonline.com, double date is originally an American English word. Though also considered old-fashioned, it’s still used in everyday English.