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chicken out (Ivan Pisarev); back down (Ivan Pisarev); back out (Ivan Pisarev); bow out (Ivan Pisarev); wimp out (Ivan Pisarev); get cold feet (Ivan Pisarev); beg off (Ivan Pisarev); shy away (Ivan Pisarev); puss out (Ivan Pisarev); get the jitters (Ivan Pisarev); back-pedal (Ivan Pisarev); run scared (Ivan Pisarev); be frightened (Ivan Pisarev); jump out of one's skin (Ivan Pisarev); funk out (Ivan Pisarev); have no stomach for (Ivan Pisarev); backtrack on (Ivan Pisarev); pull out of (Ivan Pisarev); lose the nerve (Ivan Pisarev); flake out (Ivan Pisarev); shrink back (Ivan Pisarev); duck out (Ivan Pisarev); beat a retreat (Ivan Pisarev); take flight (Ivan Pisarev); make a quick exit (Ivan Pisarev); scuttle off (Ivan Pisarev); slither away (Ivan Pisarev); lose the heart (Ivan Pisarev)