see rein (n.). Figurative sense "means of controlling; control, check, restraint" is from early 14c.
reincarnate
reincarnation
reindeer
reinforce
reinforcement
reins
reinstall
reinstate
reinstatement
reintegrate
reintegration
)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}