The Collaborative International Dictionary of English v.0.48:

Otherguise \Oth"er*guise`\ ([u^][th]"[~e]r*g[imac]z`),
Otherguess \Oth"er*guess`\, a. & adv. [A corruption of
   othergates.]
   Of another kind or sort; in another way. "Otherguess
   arguments." --Berkeley.
   [1913 Webster]