[The phrase why not? (WHY 4 b) used as a sb.] a. An argument of the form ‘Why not?,’ which attempts to leave the opponent without a reply. b. In Backgammon: see quot. 1680; hence allusively, esp. in phr. to take (have, etc.) at a why-not, i.e., at an advantage or in a dilemma.
1611. W. Sclater, Key, 123. That is answere sufficient to all such plausible why-nots.
a. 1612. Harington, in Nugæ Antiq. (1804), II. 144. This game … by certaine bootie play betweene a Protector and a Bishop, (I suppose it was at Tick-take), was like to have been lost with a why not?
1664. Butler, Hud., II. ii. 530. O’er-reach’d your Rabbins of the Synod And snap’d their Cannons with a Why-not.
1680. Cotton, Compl. Gamester, 113. This is the plain Game of Tick-Tack, which is called so from Touch, and take, for if you touch a man you must play him though to your loss; and if you hit your Adversary and neglect the advantage, you are taken with a Why-not, which is the loss of one.
c. 1680. in Verney Mem. (1904), II. 335. You catch me with a why-not still: Indeed my memory growes bad…, and things go out as fast as they come into my head now.
1720. Mrs. Manley, Power of Love (1741), 285. He took me at a why not! naked, without Cloaths and Weapons.
1753. Richardson, Grandison (1754), VI. 142. Now, Dame Selby, I have you at a why-not.
