ETYMOLOGY
from belly + mountain + -ed
EXAMPLE
“… and such a one he confesseth himself, that some of his own kindred (whom therefore he styles Jewish Presbyterians) suspect him to be; yea he complains of, or exclaims rather against one, (whom he calls a man of pufpast, like that fat bellie-mountaind Bishop) who lighting on one of his Works, said no more of it, but wrote onely upon it, Spalatensis. …”
From: A Discours Apologetical; wherein Lilies lewd and lowd lies in his Merlin or Pasqil for the yeer 1654. are cleerly laid open
By Thomas Gataker, 1654
Lexicophilia 