Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
autochthonic is an adjective meaning "originating where it is found". It carries one recorded sense.
originating where it is found
“the autochthonal fauna of Australia includes the kangaroo”
“autochthonous rocks and people and folktales”
“endemic folkways”
“the Ainu are indigenous to the northernmost islands of Japan”
Definitions, synonyms and semantic relations for autochthonic come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.