Definition of "bepissed"

...So Ditton and Whiston may both be bepissed onAnd Whiston and Ditton may both be beshit on.Sing Ditton beshit on, and Whiston bepissed on.Sing Ditton and Whiston, and Whiston and Ditton,Beshit and bepissed on, bepissed on and beshit on.

1714, Ode, to Music. On the Longitude‎, Jonathan Swift