Verb

1. To make impossible another's intended goal of sexual intercourse.
2. Derived from #1, Preventing someone from achieving a goal, aggressively getting in someone's way.

Noun

1. A person who deliberately or inadvertently makes impossible another's intended goal of sexual intercourse.
2. Derived from #1, something designed to prevent one from achieving a goal (e.g. an intentionally difficult level of video game)