underpaid
v. B2 Upper Intermediate US //ˈəndɝˈpeɪd// UK //ˌʌndəpˈeɪd// un·der·paid
v. to pay someone less money than they deserve or than is fair for the work they do.
v. to pay a person less than the amount they are entitled to or than is considered fair for their service or labor.
The company underpaid the workers for their overtime.
Many employees felt they were underpaid for the long hours they worked during the busy holiday season.
The legal team argued that the contractor had been systematically underpaid for the specialized skills required to complete the infrastructure project on time.
From under- + paid.