The Collaborative International Dictionary of English v.0.48:

Batful \Bat"ful\ (b[a^]t"f[.u]l), a. [Icel. bati amelioration,
   batna to grow better; akin to AS. bet better. Goth. ga-batnan
   to profit. [root]255. Cf. Batten, v. i., Better.]
   Rich; fertile. [Obs.] "Batful valleys." --Drayton.
   [1913 Webster]