Odd and Variable

adjective

• Not divisible by two.
  • synonyms: uneven
• Not easily explained.
  • usage: "it is odd that his name is never mentioned"
• An indefinite quantity more than that specified.
  • usage: "invited 30-odd guests"
• Beyond or deviating from the usual or expected.
  • usage: "a curious hybrid accent"; "her speech has a funny twang"; "they have some funny ideas about war"; "had an odd name"; "the peculiar aromatic odor of cloves"; "something definitely queer about this town"; "what a rum fellow"; "singular behavior"
  • synonyms: curious, funny, peculiar, queer, rum, rummy, singular
• Of the remaining member of a pair, of socks e. G..
  • synonyms: unmatched, unmated, unpaired
• Not used up.
  • usage: "leftover meatloaf"; "she had a little money left over so she went to a movie"; "some odd dollars left"; "saved the remaining sandwiches for supper"; "unexpended provisions"
  • synonyms: leftover, left over, left, remaining, unexpended

• (superl.) Remaining over; unconnected; detached; fragmentary; hence, occasional; inconsiderable; as, odd jobs; odd minutes; odd trifles.
• (superl.) Left over after a definite round number has been taken or mentioned; indefinitely, but not greatly, exceeding a specified number; extra.
• (superl.) Not divisible by 2 without a remainder; not capable of being evenly paired, one unit with another; as, 1, 3, 7, 9, 11, etc., are odd numbers.
• (superl.) Not paired with another or remaining over after a pairing; without a mate; unmatched; single; as, an odd shoe; an odd glove.
• (superl.) Different from what is usual or common; unusual; singular; peculiar; unique; strange.

• Norse: Point
• Norwegian: Possibly derived from Old Norse oddr meaning "point of a sword"

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.