1. trans. To free from being stopped up or closed.
(a) 1398. Trevisa, Barth. De P. R., XVII. xiii. (Bodl. MS.). Comyn merche vnstoppeþ and openeþ þe splene and brekeþ þe stone.
c. 1489. Caxton, Sonnes of Aymon, xii. 306. He … vnbounde hym and vnstopped his eyen.
c. 1561. Veron, Free-will, 57 b. Except the Lorde did by his holy spirit lyghten their harts vnstop their eares, and cleare the eyes of theyr myndes.
1584. Cogan, Haven Health, ix. 31. It maketh … the bellie laxatiue,… and vnstoppeth the veines.
1611. Bible, Isaiah, xxxv. 5. Then … the eares of the deafe shalbe vnstopped.
1637. N. Whiting, Albino & Bellama, 1963. Who will not … Galen try, To weaken humours, and unstop the pores?
1700. Motteux, Quix. (1733), II. 186. The first thing we did was to unty the Hands of Zoraida’s Father, and to unstop his Mouth.
1809. Malkin, Gil Blas, VI. vii. ¶ 9. My heart was softened, and my ears unstopped.
1871. Spurgeon, Treas. Dav., Ps. li. 15. He … fears to speak till the Lord unstops his shame-silenced mouth.
(b) 1530. Palsgr., 768/2. Unstoppe nat the bottell tyll we shall drinke on it.
1584. B. R., trans. Herodotus, II. 102. Priuily vnstopping one or two of hys bottles, the wyne flowed out.
1604. E. G[rimstone], D’Acosta’s Hist. Indies, IV. xii. 241. When the melting is finished, they vnstoppe the pottes and draw forth the mettall.
1645–50. Boate, Ireland’s Nat. Hist., xvii. § 7 (1652), 138. The Iron it self descendeth to the lowest part of the furnace, called the Hearth; the which being filled,… they unstop the Hearth, and open the mouth thereof.
1660. Boyle, New Exp. Phys. Mech., i. 21. To unstop the Valve to let out any Air.
1742. Lond. & Country Brew., I. (ed. 4), 73. In the Spring you must unstop your Vent-hole, and thereby see whether your Drink doth ferment or not.
1758. Reid, trans. Macquer’s Chym., I. 265. Unstop all the registers of the reverberatory.
1823. J. Badcock, Dom. Amusem., 45. If the bottle be stopped, the colour will presently disappear; but when it is unstopped, the colour soon returns again.
1854. Hull Improv. Act, 32. [To] make, rebuild, clear out, unstop, or in anywise alter any sewer.
1866. Furnivall, Bk. Quinte Essence, 4, marg. After many days unstop your distiller.
transf. 1664. Boyle, Exper. Colours, 35. Such White Fumes I have seen afforded by unstopping a Liquor.
b. intr. To become opened.
c. 1440. Ipomydon, 1261. Ipomydon was sore travailed…. Hys arme vnstoppid; þe blode gan falle.
2. To pull or draw out (an organ-stop).
1855. Browning, Master Hugues, 139. Say the word, straight I unstop the Full-Organ, Blare out the mode Palestrina.
3. (See STOP v. 28.)
1840. R. H. Dana, Bef. Mast, xxv. They were heave-ho-ing, stopping and unstopping, pawling, catting, and fishing for three hours.
Hence Unstopping vbl. sb.
1611. Cotgr., Desbouchement, an vnstopping.
1660. Boyle, New Exp. Phys. Mech., xxxvii. 314. Upon the unstopping of the Glass.
1676. More, Remarks, 83. Upon the unstopping of the lower end, all the water … will run down.
