nonachiever

[non-uh-chee-ver]
noun
  1. a student who fares poorly in the classroom or has failing grades.
  2. any person who does not succeed or progress, especially because of lack of interest or motivation.

Origin of nonachiever

1970–75; non- + achiever
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018