adj. 1 having sound judgement; moderate; ready to listen to reason. 2 in accordance with reason; not absurd. 3 a within the limits of reason; not greatly less or more than might be expected. b inexpensive; not extortionate. c tolerable, fair. 4 archaic endowed with the faculty of reason. reasonableness n. reasonably adv.
[ ME f. OF raisonable (as REASON) after L rationabilis ]