say it: ek-struh-tur-EH-stree-uhl
extraterrestrial is a noun and adjective meaning "a form of life assumed to exist outside the Earth or its atmosphere". It carries 2 recorded senses.
a form of life assumed to exist outside the Earth or its atmosphere
originating or located or occurring outside Earth or its atmosphere
“is there extraterrestrial life?”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for extraterrestrial come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.