The Collaborative International Dictionary of English v.0.48:

Bovate \Bo"vate\, n. [LL. bovata, fr. bos, bovis, ox.] (O. Eng.
   Law.)
   An oxgang, or as much land as an ox can plow in a year; an
   ancient measure of land, of indefinite quantity, but usually
   estimated at fifteen acres.
   [1913 Webster]