- inexorable
- 1550s, from L. inexorabilis "that cannot be moved by entreaty," from in- "not" + exorabilis "able to be entreated," from exorare "to prevail upon," from ex- "out" + orare "pray."
- exorable
- 16c., from L. exorabilis, from exorare (see inexorable).
- infest
- late 15c., "to attack, assail, hurt, distress, annoy," from M.Fr. infester, from L. infestare "to attack, disturb, trouble," from infestus "hostile, dangerous," originally "inexorable, not able to be handled," from in- "not" + -festus "(able to be) seized." Sense of "swarm over in large numbers" first recorded c.1600.