germ theory germ stock • germ track · · · Info · Definitions · Synonyms · Characters · · germ theory · · Text Common · · Latin · · Scripts 11 · · Length Definitions · · · (noun) (medicine) the theory that all contagious diseases are caused by microorganisms. · · Noun Definition 1 Synonyms · · · source · · Synonym 1 seed · · Synonym 2 germ · · Synonym 3 microbe · · Synonym 4 bug · · Synonym 5 Characters · · space U+0020 e latin small letter e U+0065 g latin small letter g U+0067 h latin small letter h U+0068 m latin small letter m U+006D o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074 y latin small letter y U+0079