Nowheres means not anywhere.
When someone is nowheres, they are not in any place.
Examples:
I looked for my toy nowheres, but I couldn't find it.
She searched nowheres for her missing sock.
The cat is nowheres to be found.
I checked my pockets nowheres, and it wasn't there.
He looked nowheres in the house, but the keys were in his pocket all along.
The treasure was nowheres near the old tree.