(n): a separate and self-contained entity
(n): a quantity that can assume any of a set of values
(n): the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable
(n): a star that varies noticeably in brightness
(n): (astronomy) a celestial body of hot gases that radiates energy derived from thermonuclear reactions in the interior
(n): a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity
(n): an arbitrary sign (written or printed) that has acquired a conventional significance
(adj): vs. invariable) -- (liable to or capable of change
(adj): subject to change
(adj): changing so that interrelations with another variable quantity or set of quantities remain unchanged
(adj): pertaining to any procedure involving two or more variables
(adj): taking on different forms
(adj): continuously varying
(adj): exhibiting variation and change
(adj): changeable or inconstant
(adj): marked by diversity or difference
(adj): vs. unvaried) -- (characterized by variety
(adj): (used of a device) designed so that a property (as e.g. light) can be varied
(adj): vs. unadaptable) -- (capable of adapting (of becoming or being made suitable) to a particular situation or use