From the Welsh meaning "valley".

What does the name Glyn mean?

In Welsh Baby Names the meaning of the name Glyn is: Valley.

Where does the name Glyn originate from?

Welsh and Cornish: topographic name for someone who lived in a valley, Welsh glyn, Cornish glin, or a habitational name from a place named with this word. Morgan proposes Glynllifon in Caernarfon as a probably source of the Welsh surname. Irish: reduced form of Gaelic Mag Fhloinn (see McGlynn).