brain-fag brainfag • brain fever · · · Info · Definitions · Synonyms · Characters · · brain-fag · · Text Common · · Latin · · Scripts 9 · · Length 2 · · Syllables Definitions · · · (noun) exhaustion that affects mental keenness. Synonyms: mental exhaustion. · · Noun Definition 1 Synonyms · · · mental exhaustion · · Synonym 1 Characters · · - hyphen-minus U+002D a latin small letter a U+0061 b latin small letter b U+0062 f latin small letter f U+0066 g latin small letter g U+0067 i latin small letter i U+0069 n latin small letter n U+006E r latin small letter r U+0072