IPA: /ˈʌndərˌkʊk/
KK: /ˈʌndərˌkʊk/
To cook food for a shorter time than necessary, so that it is not fully cooked.
If you undercook the chicken, it can be unsafe to eat.
Past: undercooked
Past Participle: undercooked
Undercook is formed from "under-" (meaning below or insufficiently) and "cook" (from Old English "coc", meaning to prepare food). The word refers to cooking food insufficiently or not fully cooking it.
Think of cooking something 'insufficiently' ('under-') — that's why undercook means to not cook food enough.
No commonly confused words.