inculcate (v.)

"heel-bone," 1751, from Latin (os) calcaneum "bone of the heel," from calcem (nominative calx (1)) "heel," a word of uncertain origin, perhaps from Etruscan. De Vaan lists as possible cognates Old Prussian culczi "hip," Lithuanian kulkšnis "ankle-(bone)," Bulgarian kalka "hip, thigh." Related: Calcaneal.

"act of impressing upon the mind by repeated admonitions; forcible or persistent teaching," 1550s, from inculcate (v.), or else Late Latin inculcationem (nominative inculcatio), noun of action from past-participle stem of inculcare "to force upon; stamp in."

Proto-Indo-European root meaning "in."

It forms all or part of: and; atoll; dysentery; embargo; embarrass; embryo; empire; employ; en- (1) "in; into;" en- (2) "near, at, in, on, within;" enclave; endo-; enema; engine; enoptomancy; enter; enteric; enteritis; entero-; entice; ento-; entrails; envoy; envy; episode; esoteric; imbroglio; immolate; immure; impede; impend; impetus; important; impostor; impresario; impromptu; in; in- (2) "into, in, on, upon;" inchoate; incite; increase; inculcate; incumbent; industry; indigence; inflict; ingenuous; ingest; inly; inmost; inn; innate; inner; innuendo; inoculate; insignia; instant; intaglio; inter-; interim; interior; intern; internal; intestine; intimate (adj.) "closely acquainted, very familiar;" intra-; intricate; intrinsic; intro-; introduce; introduction; introit; introspect; invert; mesentery.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit antara- "interior;" Greek en "in," eis "into," endon "within;" Latin in "in, into," intro "inward," intra "inside, within;" Old Irish in, Welsh yn, Old Church Slavonic on-, Old English in "in, into," inne "within, inside."