say it: uhl-truh-VAHY-uh-lit
ultraviolet is a noun and adjective meaning "radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays". It carries 2 recorded senses.
radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays
having or employing wavelengths shorter than light but longer than X-rays; lying outside the visible spectrum at its violet end
“ultraviolet radiation”
“an ultraviolet lamp”
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 ultraviolet 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.