A fragment is a piece broken off from something larger. In the Gospel accounts of the loaves, the word refers to the broken portions remaining after distribution, not merely crumbs left by those who ate.
The term occurs in the plural in the Gospel accounts of the miracles of the loaves and in related references. The remaining pieces were portions into which Jesus had broken the loaves before distribution, emphasizing the abundance of the miracle.
The Greek term comes from a verb meaning to break. Because the loaves were thin cakes normally broken before distribution, the Revised Version’s “broken pieces” more clearly represents the sense than “fragments” or “broken meat.”