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).
octavo
octo-
October
Octobrist
octogenarian
octopod
octopus
octoroon
octuple
ocular
oculist