undiscovered
Undiscovered (adj) means not yet found or identified; still unknown. Example: “Scientists believe thousands of species remain undiscovered in the deep ocean.”
How to use undiscovered
Learner’s notesIn plain EnglishNobody has found it or learned about it yet.
Fill the gap
Can you complete this real example?
Scientists believe thousands of species remain _____ in the deep ocean.
Etymology
From un- ("not") plus discovered, the past participle of discover.