A bartlett - A short, clumsy, dumb kid who’s not quite a midget, but not

A short, clumsy, dumb kid who’s not quite a midget, but not quite average. They trip, fall, and get confused by basic math.

'He’s a bartlett, fell into the pool and couldn’t swim.'

'She’s a bartlett, failed math and still doesn’t get fractions.'

'They’re bartletts, trip over everything and still think they're smart.'