calcitrant (adj.)

"refusing to submit, not submissive or compliant," 1823, from French récalcitrant, literally "kicking back" (17c.-18c.), from Late Latin recalcitrantem (nominative recalcitrans), present participle of recalcitrare "to kick back" (of horses), also "be inaccessible," in Late Latin "to be petulant or disobedient;" from re- "back" (see re-) + Latin calcitrare "to kick," from calx (genitive calcis) "heel" (see calcaneus). Used from 1797 as a French word in English.