cell theory cell tester • cell wall · · · Info · Definitions · Synonyms · Characters · · cell theory · · Text Common · · Latin · · Scripts 11 · · Length 4 · · Syllables Definitions · · · (noun) (biology) the theory that cells form the fundamental structural and functional units of all living organisms; proposed in 1838 by Matthias Schleiden and by Theodor Schwann. Synonyms: cell theory, cell doctrine. · · Noun Definition 1 Synonyms · · · cell doctrine · · Synonym 1 Characters · · space U+0020 c latin small letter c U+0063 e latin small letter e U+0065 h latin small letter h U+0068 l latin small letter l U+006C 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