–verb (used with object), verb (used without object)
to perform less well than (another of its kind, a general average, etc.) or less well than expected: Surprisingly, the stock has underperformed the market indexes all year. Several of our best players consistently underperform.
un·der·per·form (ŭn'dər-pər-fôrm') v.
un·der·per·formed, un·der·per·form·ing, un·der·per·forms
v.
tr.
To perform not as well as (something else): three stocks that underperformed the market as a whole.
To perform (a musical or theatrical work, for example) too seldom: In recent years, her plays have been underperformed.
v.
intr. To exhibit a level of performance that is below the standard: Defense industry companies have underperformed during the last two quarters. un'der·per·for'mance n., un'der·per·form'er n.