whoa (interj.)
1620s, a cry to call attention from a distance, a variant of who. As a command to stop a horse, it is attested from 1843, a variant of ho. As an expression of delight or surprise (1980s) it has gradually superseded wow, which was very popular 1960s.
)window.location='https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=byronic106@yahoo.com&lc=US&item_name=Donation+to +Help+Keep+Etymonline+Free+and+Open&no_note=0&cn=&curency_code=USD&bn=PP-DonationsBF:btn_donateCC_LG.gif:NonHosted'){kind=link}