a rum go

dated An odd, strange, or surprising occurrence, situation, or turn of events, especially one that might be considered somewhat disreputable or distasteful. Primarily heard in UK. A young man taking a wife so much older than himself? My word, what a rum go that is! Well, this is a rum go if I've ever seen one: the kitchen porter has just been made the head chef! You saw a lady in the professor's private chambers? Indeed, that's quite a rum go.