say it: AW-tuhm
autumn is a noun meaning "the season when the leaves fall from the trees". It is pronounced /ˈɔtəm/ — AW-tuhm. It carries one recorded sense.
the season when the leaves fall from the trees
“in the fall of 1973”
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 autumn 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.