plural of sylvanite

The creation of permanent dwellings at sea, especially outside the territory claimed by any national government.

A sound wave, of the same amplitude but of opposite phase to that of an unwanted sound, that can neutralize the unwanted sound using destructive interference.

(chiefly uncountable, literary) Anguish, grief, misery, or sorrow. / (countable, economics, ethics) In economics and utilitarianism: a unit of pain used to theoretically weigh people's outcomes.