っぱなしkeep ...-ing, have been ...-ing, leaving (something) on, leaving (something) still in use

Common

1. Suffix

   1. 1.

      leaving (on, open, unfinished, etc.)

      Usually written using kana alone, after the -masu stem of a verb; indicates that something is left in an improper state

   2. 2.

      (doing) continuously, constantly, keep ...-ing

      Usually written using kana alone, after the -masu stem of a verb