Batement \Bate"ment\, n. [For {Abatement}. See 2d {Bate}.]
Abatement; diminution. --Moxon.
[1913 Webster]
{Batement light} (Arch.), a window or one division of a
window having vertical sides, but with the sill not
horizontal, as where it follows the rake of a staircase.
[1913 Webster]