mid-15c., "plausibly," from probable + -ly (2). As a general purpose qualifier, 1610s.
He is probably out of the country
he will probably win the election
proactive
pro-am
probabilistic
probability
probable
probably
proband
probate
probation
probative
probe
)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}