Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
reasonable (adj.)
meaning “acceptable, willing to listen to reason, sensible, displaying common sense,” and the like, has long been Standard in all these senses. It is also Standard in the sense “not expensive” or “not too expensive,” as in I thought their prices were reasonable when compared with the competition’s. This use can be ambiguous when the adjective modifies something that could conceivably be able to reason, as in Chickens are reasonable this week, but I’m afraid beef is not.
