Variable and Variation

noun

• Something that is likely to vary; something that is subject to variation.
  • usage: "the weather is one variable to be considered"
• A quantity that can assume any of a set of values.
  • synonyms: variable quantity
• A star that varies noticeably in brightness.
  • synonyms: variable star
• A symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity.

adjective

• Liable to or capable of change.
  • usage: "rainfall in the tropics is notoriously variable"; "variable winds"; "variable expenses"
• Marked by diversity or difference.
  • usage: "the varying angles of roof slope"; "nature is infinitely variable"
  • synonyms: varying
• Used of a device) designed so that a property (as e. G. Light) can be varied. (
  • usage: "a variable capacitor"; "variable filters in front of the mercury xenon lights"

• (n.) Those parts of the sea where a steady wind is not expected, especially the parts between the trade-wind belts.
• (n.) That which is variable; that which varies or is subject to change.
• (a.) Liable to vary; too susceptible of change; mutable; fickle; unsteady; inconstant; as, the affections of men are variable; passions are variable.
• (n.) A quantity which may increase or decrease; a quantity which admits of an infinite number of values in the same expression; a variable quantity; as, in the equation x2 - y2 = R2, x and y are variables.
• (a.) Having the capacity of varying or changing; capable of alternation in any manner; changeable; as, variable winds or seasons; a variable quantity.
• (n.) A shifting wind or one that varies in force.

Variable is an element in a model. For example, in the model RS&Pt+1 = a + b Tbill t + et, where RS&Pt+1 is the return on the S&P in month t+1 and Tbill is the Tbill return at month t, both RS&P and Tbill are "variables" because they change through time; i. E., they are not constant.

noun

• An instance of change; the rate or magnitude of change.
  • synonyms: fluctuation
• An activity that varies from a norm or standard.
  • usage: "any variation in his routine was immediately reported"
  • synonyms: variance
• A repetition of a musical theme in which it is modified or embellished.
• Something a little different from others of the same type.
  • usage: "an experimental version of the night fighter"; "a variant of the same word"; "an emery wheel is the modern variation of a grindstone"; "the boy is a younger edition of his father"
  • synonyms: version, variant, edition
• An artifact that deviates from a norm or standard.
  • usage: "he patented a variation on the sandal"
• The angle (at a particular location) between magnetic north and true north.
  • synonyms: magnetic declination, magnetic variation
• The process of varying or being varied.
• Astronomy) any perturbation of the mean motion or orbit of a planet or satellite (especially a perturbation of the earth's moon. ()
• Biology) an organism that has characteristics resulting from chromosomal alteration.
  • synonyms: mutant, mutation, sport
• Ballet) a solo dance or dance figure.
  • synonyms: pas seul
• The act of changing or altering something slightly but noticeably from the norm or standard.
  • usage: "who is responsible for these variations in taxation"

• (n.) Extent to which a thing varies; amount of departure from a position or state; amount or rate of change.
• (n.) Change of termination of words, as in declension, conjugation, derivation, etc.
• (n.) The act of varying; a partial change in the form, position, state or qualities of a thing; modification; alternation; mutation; diversity; deviation; as, a variation of color in different lights; a variation in size; variation of language.
• (n.) One of the different arrangements which can be made of any number of quantities taking a certain number of them together.
• (n.) Repetition of a theme or melody with fanciful embellishments or modifications, in time, tune or harmony or sometimes change of key; the presentation of a musical thought in new and varied aspects, yet so that the essential features of the original shall still preserve their identity.

Variation is a change to any part of a loan contract.