also main-line, "inject (drugs) intravenously," 1934, from main line in American English slang sense "principal vein into which drugs can be injected" (1933).
main line
Main Street
Maine
mainframe
mainland
mainline
mainly
mainmast
mainsail
mainspring
mainstay
)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}