blur (n.)youdaoicibaDictYouDict[blur 词源字典]
1540s, "smear on the surface of writing;" perhaps akin to blear. Extended sense of "confused dimness" is from 1860.[blur etymology, blur origin, 英语词源]
blur (v.)youdaoicibaDictYouDict
1580s, and thus probably from blur (n.), but the dates are close and either might be the original. Related: Blurred; blurring.