__ over (topple) (4)
(Other definitions for tip that I've seen before include "Useful hint; end" , "Small amount" , "Clue" , "Helpful suggestion" , "tiny reward" .)
(Other definitions for keel that I've seen before include "Part of ship's hull" , "Ship's bottom" , "Cool, or it used to be" , "Long part on a boat's bottom" , "Ship (poet.); its bottom" .)