The Collaborative International Dictionary
Unmasterable
Unmasterable \Un*mas"ter*a*ble\, a.
Incapable of being mastered or subdued. [Obs.]
--Sir T.
Browne.
Wiktionary
unmasterable
a. Not masterable; that cannot be mastered.
Usage examples of "unmasterable".
But how was it within the vail of the heart and teeming mind, where the currents and counter-currents of that subtle but powerful passion flow and clash unseen, often gaining their full height and unmasterable strength before any event shall occur to betray their existence to the public.