1779, French, literally "on the way" (see route (n.)).
*en
-en
en bloc
en masse
en passant
en route
en suite
enable
enabler
enact
enactment
)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}