1834, "fact or condition of being relative" (apparently coined by Coleridge, of God, in "Notes on Waterland's Vindication of Christ's Divinity"), from relative (adj.) + -ity. In scientific use, connected to the theory of Albert Einstein (1879-1955), published 1905 (special theory of relativity) and 1915 (general theory of relativity), but the word was used in roughly this sense by J.C. Maxwell in 1876.
)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}