...of either Purple or Blue, but I don't know the "4th word"

I already have Yellow and Green.

I think it's an outburst, like - "RATS", "NUTS" ... and I think the 3rd one is "FUDGE"...? But can't think of the 4th word and I've guessed wrong 3x

I think the 4th Connection might be "SLOPE", "BANK".... but I can't think where "FONT" and "BED" fit into either of those Connections.

This game is fun... but drives me up a wall most of the time.