The name Shannyn means Straw Worker and is of Irish origin. Shannyn is name that's been used by parents who are considering unisex or non-gendered baby names--baby names that can be used for any gender.

From the Gaelic “O’Sionain,” an occupational surname for someone who worked with straw.

May also reference the longest river in Ireland, the Shannon. Possibly in reference to the Old Irish sen meaning "old, ancient."