underachieve
1. [ verb ] perform less well or with less success than expected
Synonyms: underperform
Examples:

"John consistently underachieves, although he is very able" "My stocks underperformed last year"

Related terms: do underachiever
Similar spelling:   underachiever
  unweathered
  underactive
  underrate
  undersurface
  underdevelop
  unattractive
  underneath
  understate
  underrating
  underframe
  understructure
  underdeveloped
  unattractively
  underived
  underhanded
  undercharge