either oil that restores wood to its natural luster and hardness or a girl that is hot enough to give a guy a boner thus restoring his wood to its natural luster and hardness.
guy1 walks in wearing butt shorts guy2:"what a wood killer!"
guy1:"assuming you had wood"
a girl in a tube top walks in
guys1and2:"wow who's the teak oil!"
Someone who intentionally attacks his own players in an online game.
Teamkilling in games originated by people exploiting game servers that accepted 'friendly fire'.
More recently, celebrity gaming figures like LOLMAN have utilised impact circles of weapons so as to become profficient at teamkilling, even without 'friendly fire' enabled. In games like Unreal Tournament, this works by firing a projectile in the right place, so that the force of impact makes a teammate fly so far that he loses a frag due to fall damage. This is a 'teamkill'.