John Gill Commentary 1 Kings 11:20

"And the sister of Tahpenes bare him Genubath his son, whom Tahpenes weaned in Pharaoh`s house; and Genubath was in Pharaoh`s house among the sons of Pharaoh." — 1 Kings 11:20 (ASV)

And the sister of Tahpenes bore him Genubath his son

Which signifies "stealth", and the name might be given in memory of himself being carried away by stealth from his own land:

whom Tahpenes weaned in Pharaoh's house :

who was so fond of the child, that she took it, and weaned it for her in the king's palace:

and Genubath was in Pharaoh's household among the sons of Pharaoh ;

brought up among them, as if he was one of them.