throwaway

Short definition from Wiktionary

Adjective

1. 1
   Disposable; intended for a single use prior to being discarded.
2. 2
   Extemporaneous; off the cuff.
3. 3
   Given in a casual manner, either deliberately or unconsciously, with apparent disregard for effect.

Noun

1. 1
   Something temporary and disposable, as: Any printed material that need not be kept after being read; especially, a flyer or brochure.
2. 2
   Something temporary and disposable, as: A burner account.