Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
supernumerary is a noun and adjective meaning "a person serving no apparent function". It carries 3 recorded senses.
a person serving no apparent function
“reducing staff is difficult because our employees include no supernumeraries”
a minor actor in crowd scenes
more than is needed, desired, or required
“trying to lose excess weight”
“found some extra change lying on the dresser”
“yet another book on heraldry might be thought redundant”
“skills made redundant by technological advance”
“sleeping in the spare room”
“supernumerary ornamentation”
“it was supererogatory of her to gloat”
“delete superfluous (or unnecessary) words”
“extra ribs as well as other supernumerary internal parts”
“surplus cheese distributed to the needy”
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 supernumerary come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.