1520s, "to enclose with stakes, fence in," from Middle French empaler and directly from Medieval Latin impalare "to push onto a stake," from assimilated form of in- "into, in" (see in-(2)) + Latin palus "a stake, prop, stay; wooden post, pole," from PIE *pak-slo-, from root *pag-/*pak- "to fasten" (see pact). Sense of "pierce with a pointed stake" (as torture or punishment) first recorded 1610s. Related: Impaled; impaling.