The term 'muffin' can be broken down into four crossword solutions: GEM (3 letters), STUD (4 letters), BRAN (4 letters), and POPOVER (7 letters). GEM is a precious stone, usually cut and polished for use in jewelry. STUD is a metal pin or screw with a head on one end and a threaded shaft on the other, used for fastening objects together. BRAN is the hard outer layer of cereal grains, such as wheat, oats, and barley. POPOVER is a light, hollow roll made from an egg batter similar to that used for Yorkshire pudding.