when one goes out on a date with a friend. this could be when two friends decide to try a date, or if two friends decide to go out to an event as friends.
"Dude, Frankie and Ady are going to prom as friendates."
A planned outing involving two friends. Could be a potential relationship, but doesn't have to be; two straight, same-gender friends could go on a friendate.
Girl 1: Wanna go get our nails done on Friday?
Girl 2: Sure!! Maybe we could go out to lunch, too.
Girl 1: YES!!! Movie? We could make a whole day of it! Friendate!!