/ Dictionary / Index H high-octane: Meaning and Definition of Find definitions for: high-oc•tane Pronunciation: (hī'ok'tān), [key] — adj. noting a gasoline with a relatively high octane number, characterized by high efficiency and freedom from knock. forceful or intense; dynamic; high-powered: high-octane efforts to obliterate the competition. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: high-octane (Thesaurus) high-occupancy vehicle lane high-pitched Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language