Definition of floof:
(n) :
(Internet slang, countable, endearing) A long-haired dog, cat, or similar furry pet animal.
(n) :
(Internet slang, uncountable, endearing) The fur of such an animal.
(n) :
(Internet slang, uncountable, endearing) Hair that looks fluffy, like fur from such an animal.
(v) :
(transitive, informal, often humorous) To make something fluffy; to fluff (up).
(v) :
(intransitive, informal) To move in a floofy or fluffy manner.