crumb

crumb
crumb /krʌm/ noun [countable]1. a very small piece of dry food, especially bread or cake:
    She stood up to brush the crumbs off her uniform.
    Coat with bread crumbs and bake.
2. a very small amount of something
    crumb of comfort/hope/affection etc
    There was only one crumb of comfort – Alex hadn’t said anything to Jeff.
     

THESAURUS

■ a small piece
   ▪ fragment a small piece that has broken off something, especially something hard: The window shattered, covering them with fragments of glass. | They found fragments of bone.
   ▪ crumb a very small piece of bread, cake etc: There were just a few crumbs left on the plate.
   ▪ speck a piece of something such as dirt or dust which is so small you almost cannot see it: She brushed the specks of dust from the table.
   ▪ drop a very small amount of a liquid: There were drops of blood on the floor. | I felt a drop of rain.