extension

noun

• The act of extending; a stretching out; enlargement in length or breadth; an increase
• The state of being extended
• That property of a body by which it occupies a portion of space (or time, e.g. "spatiotemporal extension")
• A part of a building that has been extended from the original
• Capacity of a concept or general term to include a greater or smaller number of objects; — correlative of intension.
• A written engagement on the part of a creditor, allowing a debtor further time to pay a debt.
• The operation of stretching a broken bone so as to bring the fragments into the same straight line.
• An exercise in which an arm or leg is straightened against resistance.
• A simple offensive action, consisting of extending the weapon arm forward.
• A numerical code used to specify a specific telephone in a telecommunication network.
• A file extension.

  "Files with the .txt extension usually contain text."

• An optional software component that adds functionality to an application.

  "a browser extension"

• The set of tuples of values that, used as arguments, satisfy the predicate.
• (grammar) A kind of derivative morpheme applied to verbs in Bantu languages.