underachievement underachieve • underachiever · · · Info · Definitions · Antonyms · Characters · · underachievement · · Text Latin · · Script 16 · · Length 5 · · Syllables Definitions · · · (noun) poorer than expected performance (poorer than might have been predicted from intelligence tests). · · Noun Definition 1 Antonyms · · · overachievement · · Antonym 0 Characters · · a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E r latin small letter r U+0072 t latin small letter t U+0074 u latin small letter u U+0075 v latin small letter v U+0076