substance abuse substance • substance abuser · · · Info · Definitions · Synonyms · Characters · · substance abuse · · Text Common · · Latin · · Scripts 15 · · Length 4 · · Syllables Definitions · · · (noun) excessive use of drugs. Synonyms: substance abuse, drug abuse, habit. · · Noun Definition 1 Synonyms · · · drug abuse · · Synonym 1 habit · · Synonym 2 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 e latin small letter e U+0065 n latin small letter n U+006E s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075