Probably from shavah; a gift (as available) -- present.
see HEBREW shavah
H7862. shay
שַׁי noun masculine gift offered as homage (√ dubious; perhaps in spite of שׁ = Arabic , verb wish, thing (weakened from thing desired); compare חֵפֶץ 4); — שׁ ׳יוּבַל Isaiah 18:7, שׁ ׳יֹבִילוּ Psalm 76:12, ׳יוֺב שָׁ֑י 68:30.
שׁיא
proper name, masculine 2 Samuel 20:25 Kt, see שְׁוָא