n (geometry) The part of a circle between its circumference and a chord (usually other than the diameter).
n (travel) A portion of an itinerary; can be a flight or train between two cities, a car or hotel booked in a particular city.
n (botany) A portion of an organ whose cells are derive from a single cell within the primordium from which the organ developed.
n (zoology) One of several parts of an organism, with similar structure, arranged in a chain; such as a vertebra, or a third of an insect's thorax.