(kwæk)  [f. QUACK n.¹] 

    1. intr. To play the quack.    a. To pretend to have medical knowledge; to dabble ignorantly in medicine.    b. To talk pretentiously and ignorantly, like a quack. Also with of.
 
  1628 VENNER Baths of Bathe (1650) 362 In quacking for Patients he is so kind and free of his service. 1678 BUTLER Hud. III. i. 330 To quack of universal cures. Ibid. 364 A Virtuoso, able To smatter, quack, and cant, and dabble. 1722 DE FOE Plague (Rtldg.) 45 Ignorant Fellows; quacking and tampering in Physick. 1756 C. LUCAS Ess. Waters I. Pref., Enlighten then their understandings..and who then will venture to quack, or be quacked? 1876 G. MEREDITH Beauch. Career III. ii. 29 A wiseacre who went quacking about the country, expecting to upset the order of things.
 

    2. trans. To advertise, puff, or palm off with fraudulent and boastful pretensions, as a quack-medicine or means of cure. Also with forth. to quack titles: to invent new titles for old books in order to make them sell.
 
  1651 BIGGS New Disp. Pref. 9 To be Quacked forth in Bartholmew-Fayr. 1651 CLEVELAND Poems 33 Could I (in Sir Emp'ricks tone) Speak pills in phrase, and quack destruction. 1715 S. CENTLIVRE Gotham Elect. I, My third Son is a bookseller..he has an admirable knack at quacking Titles. 1727 BRADLEY Fam. Dict. s.v. Gill ale, A notorious Imposition, which is quack'd upon the World..to be a great Restorative and Curer of Consumptions. 1830 Examiner 610/2 The Politician must be quacked, paragraphed,..and coteried into notoriety.
 

    3. To treat after the fashion of a quack; to administer quack medicines to; to seek to remedy or put right by empirical or ignorant treatment. Also with up.
 
  1746 H. WALPOLE Lett. to Mann (1833) II. 124 If he has any skill in quacking madmen, his art may perhaps be of service now. 1757 E. GRIFFITH Lett. Henry & Frances (1767) I. 84, I am..as ‘hoarse as bondage’. I shall there~fore stay here to-night, and quack myself. 1778 Sketches for Tabernacle Frames 17 For quacking Souls you cannot be attack'd. 1810 BENTHAM Packing (1821) 144 Epitaph on a Valetudinarian, who quacked himself to death. 1820 P. HAWKER Diary (1893) I. 195, I tried with bricks, baskets and everything..to quack up one of them [defective chimneys]. a1876 H. MARTINEAU Autobiog. (1877) I. 147 The less its condition is quacked..the better for the mind's health. 1925 Scribner's Mag. Oct. 385/1 Time..has not obliterated the love of being quacked.
 

    Hence quacked ppl. a.
 
  a1876 H. MARTINEAU Autobiog. (1877) II. 461 Such exhortations are too low for even the..quacked morality of a time of theological suspense.