1570s, in military sense, "an armed guard," later generally, "a protecting, guiding, or honorary guard; protection or safeguard on a journey or excursion," from French escorte (16c.), from Italian scorta, literally "a guiding," from scorgere "to guide," from Vulgar Latin *excorrigere, from ex- "out" (see ex-) + Latin corrigere "set right" (see correct (v.)). The sense of "person accompanying another to a social occasion" is 1936; as a person hired by a client for sexual services by 1974.
[fee to secure services] mid-15c., "act of keeping for oneself, an authorized retention (of dues, etc.)," an agent noun from retain (v.), or perhaps from or influenced by French retenir, infinitive used as a noun. Meaning "a retaining fee, fee paid to an attorney or barrister to secure his services" is from 1818. The general sense of "sum paid to secure special services" is from 1859.
1826 (adj.), "eight-footed or eight-armed;" 1835 (n.) "an eight-footed or eight-armed animal," especially an octopus, from Latinized form of Greek oktōpod-, stem of oktōpous (see octopus).