verb (used without object), un·der·a·chieved, un·der·a·chiev·ing.

to perform, especially academically, below the potential indicated by tests of one's mental ability or aptitude.
to perform below expectations or achieve less than expected, especially by others.

Origin of underachieve

First recorded in 1950–55; under- + achieve
Related formsun·der·a·chieve·ment, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for underachieve



(intr) to fail to achieve a performance appropriate to one's age or talents
Derived Formsunderachiever, noununderachievement, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012