noun

• (chiefly in the plural) A tiny piece of bread, either one that falls from bread as it is cut or eaten, or one made deliberately by crumbling bread.
• (graphical user interface, chiefly in the plural) A single link in a chain indicating the hierarchical location of a directory, web page or similar, used as a navigation aid.
  "Breadcrumbs usually look something like this: "Home > About Us > Staff" and are positioned near the top navigation. […] The words in the breadcrumbs are links to pages at higher levels of the website."
• (programming, chiefly in the plural) A fragment of data that serves to log the actions taken by a program, used in debugging.
  "If you believe the system can merrily proceed despite an assertion failure, code the exception handler to log the error, leaving debugging breadcrumbs behind, and return."
• (figuratively, in the plural) One in a series of clues leading to a person or place.
  "Before he died, James Halliday (Mark Rylance), the hermit-like, socially maladjusted tech genius who created The Oasis, hid an Easter egg somewhere in the circuitry, scattering bread crumbs that lead to its location. Find the egg, and the mogul’s fortune—along with total control of his digital fiefdom—is yours. It’s the ultimate capitalist scavenger hunt!"

verb

• (transitive, cooking) To sprinkle breadcrumbs on to food, normally before cooking.
  "All this breadcrumbing finished, you can put the meat on a grid over a baking dish and leave it until you are ready to cook it."
• (graphical user interface, intransitive) To add navigational breadcrumbs to (a web page or user interface).
  "Along those same lines, creating separate folders can enable you to use "breadcrumbing," which is another navigation aid (discussed in the section "Determining How to Organize the Information," later in this chapter)."