not capable of being found: an unfindable treasure.
Origin of unfindable
1785–95; un-1 + findable
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for unfindable
Historical Examples of unfindable
When the door had shut behind her he took out the necklace with the idea of secreting it in an unfindable place.Under Cover
Roi Cooper Megrue