Instance and Random

noun

• An occurrence of something.
  • usage: "it was a case of bad judgment"; "another instance occurred yesterday"; "but there is always the famous example of the Smiths"
  • synonyms: case, example
• An item of information that is typical of a class or group.
  • usage: "this patient provides a typical example of the syndrome"; "there is an example on page 10"
  • synonyms: example, illustration, representative

verb

• Clarify by giving an example of.
  • synonyms: exemplify, illustrate

• (n.) That which is instant or urgent; motive.
• (n.) That which offers itself or is offered as an illustrative case; something cited in proof or exemplification; a case occurring; an example.
• (n.) Occasion; order of occurrence.
• (n.) The act or quality of being instant or pressing; urgency; solicitation; application; suggestion; motion.
• (v.t.) To mention as a case or example; to refer to; to cite; as, to instance a fact.
• (n.) A token; a sign; a symptom or indication.
• (v.i.) To give an example.

adjective

• Lacking any definite plan or order or purpose; governed by or depending on chance.
  • usage: "a random choice"; "bombs fell at random"; "random movements"

• (n.) The direction of a rake-vein.
• (n.) Force; violence.
• (a.) Going at random or by chance; done or made at hazard or without settled direction, aim or purpose; hazarded without previous calculation; left to chance; haphazard; as, a random guess.
• (n.) Distance to which a missile is cast; range; reach; as, the random of a rifle ball.
• (n.) A roving motion; course without definite direction; want of direction, rule or method; hazard; chance; -- commonly used in the phrase at random, that is, without a settled point of direction; at hazard.

Random is a condition in finance or economics whereby changes occur on a probabilistic basis. The underlying probability function may be known or unknown.