n. & v.
n. 1 a motive, cause, or justification (has good reasons for doing this; there is no reason to be angry). 2 a fact adduced or serving as this (I can give you my reasons). 3 the intellectual faculty by which conclusions are drawn from premisses. 4 sanity (has lost his reason). 5 Logic a premiss of a syllogism, esp. a minor premiss when given after the conclusion. 6 a faculty transcending the understanding and providing a priori principles; intuition. 7 sense; sensible conduct; what is right or practical or practicable; moderation.
v. 1 intr. form or try to reach conclusions by connected thought. 2 intr. (foll. by with) use an argument (with a person) by way of persuasion. 3 tr. (foll. by that + clause) conclude or assert in argument. 4 tr. (foll. by why, whether, what + clause) discuss; ask oneself. 5 tr. (foll. by into, out of) persuade or move by argument (I reasoned them out of their fears). 6 tr. (foll. by out) think or work out (consequences etc.). 7 tr. (often as reasoned adj.) express in logical or argumentative form. 8 tr. embody reason in (an amendment etc.). by reason of owing to. in (or within) reason within the bounds of sense or moderation. it stands to reason (often foll. by that + clause) it is evident or logical. listen to reason be persuaded to act sensibly. see reason acknowledge the force of an argument. with reason justifiably. reasoner n. reasoning n. reasonless adj.
[ ME f. OF reisun, res(o)un, raisoner, ult. f. L ratio -onis f. reri rat- consider ]