abattant

Etymology
Adjective and noun derived from the present participle of, relating to the obsolete meaning "put horizontal", in which it has been replaced by.

Adjective

 * 1) flat and articulated so it can move from a horizontal to a vertical position

Noun

 * 1) a lid or flap which can move from a horizontal to a vertical position
 * 2) a toilet lid
 * 3)  any sort of flap

Usage notes

 * Despite appearances, the matching verb is, not.