Something suitable for comparison.
(often with to) Able to be compared (to).
An elephant is comparable in size to a double-decker bus.
(often with to) Similar (to); like.
Constituting a pair in a particular partial order.
Six and forty-two are comparable in the divides order, but six and nine are not.
(grammar) Said of an adjective that has a comparative and superlative form.
"Big" is a comparable adjective, since it can take the forms "bigger" and "biggest"; but "unique" is not comparable, except in disputed, but common, usage.