\In`com*pos"si*ble\, a. [Pref. in- not +
compossible: cf. F. incompossible.]
Not capable of joint existence; incompatible; inconsistent.
[Obs.]

      Ambition and faith . . . are . . . incompossible.
                                               --Jer. Taylor.
-- {In`com*pos`si*bil"i*ty}, n. [Obs.]