IPA: /ˌʌndərˈfiːd/
KK: /ʌndərˈfid/
To provide less food than is needed for proper growth or health.
The farmer realized he had underfed the livestock during the winter months.
Past: underfed
Past Participle: underfed
Underfeed → It is formed from "under-" (meaning below or insufficient) and "feed" (from Old English "fēdan", meaning to provide food). The word "underfeed" means to provide insufficient food or nourishment.
Think of providing food that is 'below' what is needed — 'under-' means below, and 'feed' means to provide food.