onion smut onion smudge • onion stem · · · Info · Definitions · Synonyms · Characters · · onion smut · · Text Common · · Latin · · Scripts 10 · · Length 3 · · Syllables Definitions · · · (noun) smut fungus causing blackish blisters on scales and leaves of onions; especially destructive to seedlings. Synonyms: onion smut, Urocystis cepulae. · · Noun Definition 1 Synonyms · · · urocystis cepulae · · Synonym 1 Characters · · space U+0020 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075