variable

Etymology

Borrowed into Middle English in the 14th century from Old French variable, from Latin variare (“to change”), from varius (“different, various”). Equates to English vary + -able.

adj

1. Able to vary or be varied.
   variable winds or seasons; a variable quantity; a variable resistor
2. Likely to vary.
3. Marked by diversity or difference.
4. (mathematics) Having no fixed quantitative value.
5. (biology) Tending to deviate from a normal or recognized type.

noun

1. Something that is variable.
2. Something whose value may be dictated or discovered.
   There are several variables to consider here.
   Bats host many high-profile viruses that can infect humans, including severe acute respiratory syndrome and Ebola. A recent study explored the ecological variables that may contribute to bats’ propensity to harbor such zoonotic diseases by comparing them with another order of common reservoir hosts: rodents. 2013 May-June, Katie L. Burke, “In the News”, in American Scientist, volume 101, number 3, page 193
3. (mathematics) A quantity that may assume any one of a set of values.
4. (mathematics) A symbol representing a variable.
5. (programming) A named memory location in which a program can store intermediate results and from which it can read them.
6. (astronomy) A variable star.
7. (nautical) A shifting wind, or one that varies in force.
8. (nautical, in the plural) Those parts of the sea where a steady wind is not expected, especially the parts between the trade-wind belts.