from Latin dēvītāre devite vb. (to shun) + -ble
1727 - An Universal Etymological English Dictionary, Nathan Bailey;
"Devitable, easy to be shunned or avoided"
From: The Touch-Stone of Common Assurances;
Or, A Plain and Familiar Treatise, Opening the Learning of the Common Assurances,
Or Conveyances of the Kingdom.
By William Sheppard, Revised and Corrected by By Edward Hilliard, 1785
Chapter 23. Of A Testament