controlled substance controlled • controller · · · Info · Definitions · Characters · · controlled substance · · Text Common · · Latin · · Scripts 20 · · Length 4 · · Syllables Definitions · · · (noun) a drug or chemical substance whose possession and use are controlled by law. Synonyms: controlled substance. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075