con*ceiv"a*ble*ness
Webster's Dictionary (GCIDE)
Conceivable \Con*ceiv"a*ble\, a. [Cf. F. concevable.] Capable of being conceived, imagined, or understood. "Any conceivable weight." --Bp. Wilkins. [1913 Webster]
It is not conceivable that it should be indeed that very person whose shape and voice it assumed. --Atterbury. -- Con*ceiv"a*ble*ness, n. -- Con*ceiv"a*bly, adv. [1913 Webster]