The Collaborative International Dictionary
Unconceivable
Unconceivable \Un`con*ceiv"a*ble\, a.
Inconceivable. [Obs.]
--Locke. -- Un`con*ceiv"a*ble*ness,
n. [Obs.] -- Un`con*ceiv"a*bly, adv. [Obs.]
Wiktionary
unconceivable
a. That cannot be conceived; unimaginable; inconceivable.