BT Zev 6a(15) :מקבעא לא מכפרא, מיקיפיא מכפרא‏ : it does not atone for something fixed, but does atone for something "floating"
See the entire entry for qḇāˁ, qḇāˁā v.n. fixing

BT Zev 6a(15) :מיקיפיא מכפרא‏ : it effects a floating atonement
See the entire entry for qp̄ē, qip̄yā n.m. floating stuff