Underrepresented Definition

ŭndər-rĕprĭ-zĕntĭd
under-represented
adjective
Present in inadequate numbers or amounts; insufficiently represented.
A minority group that was underrepresented in the government.
American Heritage

Having less than adequate or sufficient representation.

Wiktionary
verb

Simple past tense and past participle of underrepresent.

Wiktionary