IPA: /ˌʌndɪsˈkʌvərd/
KK: /ʌndɪsˈkʌvərd/
Something that has not been found or known yet.
There are many undiscovered species in the rainforest.
Undiscovered → It is formed from "un-" (meaning not) and "discovered" (from Latin "discooperire", meaning to uncover or reveal). The word "undiscovered" means not uncovered or not revealed, referring to something that has not yet been found or known.
Think of something that is 'not' ('un-') 'uncovered' or 'revealed' ('discovered') — that's why undiscovered means something that hasn't been found yet.