un ‧ der ‧ paid /ˌʌndəˈpeɪd◂ $ -ər-/ BrE AmE adjective
[ Word Family: noun : ↑ pay , ↑ payment , ↑ repayment , ↑ payer , ↑ payee ; verb : ↑ pay , ↑ repay , ↑ underpay ≠ ↑ overpay ; adjective : paid ≠ ↑ unpaid , ↑ underpaid ≠ ↑ overpaid , ↑ payable ]
earning less money than you deserve for your work:
Teachers are overworked and underpaid.