Old English sceaphierde, from sceap "sheep" (see sheep) + hierde "herder," from heord "a herd" (see herd (n.)). Similar formation in Middle Low German, Middle Dutch schaphirde, Middle High German schafhirte, German dialectal Schafhirt. Shepherds customarily were buried with a tuft of wool in hand, to prove on Doomsday their occupation and be excused for often missing Sunday church. Shepherd's pie is recorded from 1877.
fem. suffix, from French -esse, from Late Latin -issa, from Greek -issa (cognate with Old English fem. agent suffix -icge); rare in classical Greek but more common later, in diakonissa "deaconess" and other Church terms picked up by Latin.