Scottish English and Irish: ethnic name from Middle English welshe (Old English wēalisc wēlisc) ‘foreign Welsh’ for someone from Wales or a speaker of the Welsh language. Compare Walsh and Wallace . Americanized form of German Welsch . Americanized form of Ukrainian and Jewish (from Ukraine) Voloshin or its Polish variant Wołoszyn (see Woloszyn ).
Source: Dictionary of American Family Names 2nd edition, 2022