Middle English fyken "move about restlessly" (early 13c.), from Old Norse fikjask "to desire eagerly," fika (in fika sig upp "climb up nimbly," of a spider), probably from a general North Sea Germanic word related to the source of German ficken "to move about briskly." Later as "give trouble, vex" (1570s), a sense surviving especially in Scottish. Hence also fikery "vexatious trouble" (1823); fiky "causing trouble about trifles" (1768).[fike etymology, fike origin, 英语词源]