crumbum

noun

1. a very small piece broken off something; small particle or bit, esp. of bread, cake, etc.
2. any bit or scrap: crumbs of knowledge
3. the soft part of bread within the crust
4. ☆ Slang a worthless, disgusting, or despicable person
   also crumbum

transitive verb

1. Rare to crumble
2. to clear of crumbs: to crumb a table
3. Cooking to cover or thicken with crumbs