v. t. & i. [ 1st pref. un- + furl. ] To loose from a furled state; to unfold; to expand; to open or spread; as, to unfurl sails; to unfurl a flag. [ 1913 Webster ]
[はってん, hatten](n, vs) (1) development; growth; advancement; unfurling; (2) expansion; extension; enlargement; (3) (recently often associated with gay sex) (See 発展場) playing around; having an active sex life; (P)#1425[Add to Longdo]