say it: aw-TUHM-nuhl
autumnal is an adjective meaning "of or characteristic of or occurring in autumn". It carries 2 recorded senses.
of or characteristic of or occurring in autumn
“the autumnal equinox”
“autumnal fruits”
characteristic of late maturity verging on decline
“a serene autumnal mood”
Definitions, synonyms and semantic relations for autumnal 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.