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definitions

underachiever

[uhn-der-uh-chee-ver]

noun

a student who performs less well in school than would be expected on the basis of abilities indicated by intelligence and aptitude tests, etc.
a person or thing that performs below expectations.

Origin of underachiever

1945–50; under- + achiever
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for under-achiever

disappointment, also-ran, insolvent, turkey, bankrupt, dud, moocher, prodigal, derelict, incompetent, beat, deadbeat, nobody, loafer, bum, castaway, flop, loser, good-for-nothing, has-been
Word Origin and History for under-achiever
n.

also underachiever, 1953, from under + achiever (see achieve). Under-achievement is recorded from 1951.

Online Etymology Dictionary, © 2010 Douglas Harper