in·ex·o·ra·ble 
(ĭn-ĕksər-ə-bəl)
(ĭn-ĕksər-ə-bəl)adj.
1. Impossible to stop, alter, or resist; inevitable: an inexorable fate; an inexorable law of nature.
2. Not capable of being persuaded by entreaty; relentless: an inexorable opponent.
[Latin inexōrābilis : in-, not; see IN-1 + exōrābilis, pliant (from exōrāre, to prevail upon : ex-, intensive pref.; see EX- + ōrāre, to argue).]
in·ex′o·ra·bili·ty, in·exo·ra·ble·ness n.
in·exo·ra·bly adv.