1) To remove the fun from a situation (especially a competitive game.)
2) Someone who disappears for the night with a member of the opposite sex and then refuses to share the sordid details of the encounter with their friends
1) oh god, he completely cliffied that game of monopoly
Similar to cliffhanger in a TV show. When you end a kinky chat session or erotic role play to pick it up later, but it leaves you sexually aroused, because you did not "finish"
I had some real sweet erp with Jil last night, but it got late, so she left me with a cliffboner