prefanity

Coined by Penny Arcade, prefanity are words and expressions which are not yet considered profanity, but will at some point in the future become vulgar.

"That guy who just killed me in Halo is a real ham doctor"

"What's a ham doctor?"

"It's prefanity, dude. Trust me, soon it will be a worse insult than cuntburglar - just wait and see"