From Middle English gryve, grayve, from Old Norse greifi (“a count, earl, steward”), akin to Swedish and Danish greve (“a count, earl”), Old English ġerēfa (“reeve”). More at reeve.
From Middle English greve, grayve, from Old French greve (“shin”), of unknown origin.
"greeve." YourDictionary, n.d. Web. 15 May 2018. <http://www.yourdictionary.com/greeve>.
greeve. (n.d.). Retrieved May 15th, 2018, from http://www.yourdictionary.com/greeve