(Noun)A friend who is also a work colleague. Frolleagues are often created during a particularly rowdy night of work drinks and are useful as a sounding board for bitching about your work load/boss etc.

People who you work with that are more than colleagues but not quite friends. You really find them when you leave a company and you are deciding who gets the Facebook invite and who gets the LinkedIn invite.

Someone who is both a colleague and a friend. There is a thin line between a friend and a colleague - for example you would go and have some ice cream with your frolleague during office hours, but you would not go out to a club with her to do the dirty wine

Friends + colleagues - for when your love and respect for your co-workers is both immense and totally work-appropriate; with a frolleague crowd, you typically switch between being fun and relaxed, and professional depending on the context.

A colleague who is also your friend.