sea·mount 
(sēmount′)
(sēmount′)n.
An underwater mountain rising from the ocean floor and having a peaked or flat-topped summit below the surface of the sea.
- nitrogen-fixing
- nitrogenize
- nitrogen mustard
- nitrogen narcosis
- nitrogenous
- nitrogenous base
- nitrogenous base
- nitroglycerin
- nitroglycerine
- nitrohydrochloric acid
- nitromethane
- nitroparaffin
- nitrosamine
- nitrostarch
- nitrous
- nitrous acid
- nitrous oxide
- nitrox
- nits-and-lice
- nitty
- nitty-gritty
- nitwit
- Niue
- nival
- niveous