comparable

An elephant is comparable in size to a double-decker bus.

Furthermore, this increase in risk is comparable to the risk of death from leukemia after long-term exposure to benzene, another solvent, which has the well-known property of causing this type of cancer.

Six and forty-two are comparable in the divides order, but six and nine are not.

"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.