What does Shiloh mean?
Etymology unsettled. Most often read 'tranquil, peaceful, place of rest,' linked to the sanctuary town Shiloh and a root sh-l-h. The cryptic term in Genesis 49:10 is alternatively read shelo, 'he whose it is' (taken messianically). The popular gloss 'his gift' is not well supported. Hedge as disputed; used for both sexes in modern practice.
What does Shai mean?
From Hebrew shai 'gift'. The 'gift' meaning is widely cited, though the origin is disputed: some sources derive the name instead as a diminutive of Yeshayahu (Isaiah), 'God is salvation'.