blotch

Etymology

Uncertain. Perhaps a blend of blot + botch.

noun

1. An uneven patch of color or discoloration.
   1711, Joseph Addison and Richard Steele, The Spectator, London: J. & R. Tonson, 12th edition, Volume I, No. 16, p. 68, […] in healing those Blotches and Tumours which break out in the body […]
   Since the day in which this reformation began, by how many strange and critical turns has it been perfected and handed down, if not, entirely without spot or wrinkle,—at least, without great blotches or marks of anility. 1768, Laurence Sterne, Sermon VI, The Sermons of Mr. Yorick, volume 3, London: T. Becket & P.A. De Hondt, pages 182–183
   Snow lay on the croft and river-bank in undulations softer than the limbs of infancy; […] it clothed the rough turnip-field with whiteness, and made the sheep look like dark blotches; 1860, George Eliot, The Mill on the Floss, Book II, Chapter 2
   1921, Wallace Stevens, Sur Ma Guzzla Gracile, Palace of the Babies, in Poetry, Volume 19, No. 1, The disbeliever walked the moonlit place, Outside the gates of hammered serafin, Observing the moon-blotches on the walls.
2. An irregularly shaped area.
   At Coleman's Hill, the upper beds consist of yellowish, soft, gritty sandstone, containing some small calcareous fragments, a few pebbles of quartz, blotches of red shale, and fragments of sandstone with impressions of stems of plants. 1839, The Silurian System
   His shirt showed big blotches of moisture, and the sweat was rolling in clear drops along the creases in his brown neck. 1923, Willa Cather, One of Ours, Book One, Chapter 5
   Microscopic and sometimes macroscopic examination of the apparently healthy intervening tissue may reveal the fungus connecting the blotches of diseased tissue. 1938, Henry Bake Steer, Stumpage Prices of Privately Owned Timber in the United States
   Evil places where the wind whistles and the dust grates, places that are blotches of shadow, blotches of rust, blotches of oil: innumerable blotches. 2010, J.M.G. Le Clezio, The Book of Flights
3. (figurative) Imperfection; blemish on one’s reputation, stain.
   1921, Warren G. Harding, Inaugural address, in Inaugural Addresses of the Presidents of the United States: from George Washington to Barack Obama, Washington, D.C.: U.S. G.P.O., 1989, There never can be equality of rewards or possessions so long as the human plan contains varied talents and differing degrees of industry and thrift, but ours ought to be a country free from the great blotches of distressed poverty.
4. Any of various crop diseases that cause the plant to form spots.
   The fungus causing blotch lives through the winter in the cankers which it has developed on twigs, water sprouts, and fruit spurs. 1926, John William Roberts, Leslie Pierce, Apple blotch, page 3
   Blue mold and the black rot fungus are most Commonly found associated with blotch in this way. 1951, Dean Humboldt Rose, Lacy Porter McColloch, D. F. Fisher, Market Diseases of Fruits and Vegetables: Apples, Pears, Quinces
   Blotch is one of the most common and serious diseases of A. bisporus and is responsible for considerable losses. 1999, Diseases of Horticultural Crops: Vegetables, Ornamentals, and Mushrooms
   Pseudomonas is the major spoilage genus associated with blotch in fresh mushrooms. 2015, Marian Petre, Mushroom Biotechnology: Developments and Applications, page 98
5. A bright or dark spot on old film caused by dirt and loss of the gelatin covering the film, due to age and poor film quality.
   Characteristics of blotches are that they seldom appear at the same spatial location in consecutive frames, they tend to be smooth (little texture), and they usually have intensity values that are very different from the original contents they cover. 1999, Jim Byrnes, Signal Processing for Multimedia, page 173
   Films corrupted by blotches are often restored in a two-step approach. The first step detects blotches and generates binary detection masks that indicate whether each pixel is part of a blotch. The second step corrects pixels by means of spatio-temporal interpolation. 2000, A. Hanjalic, G.C. Langelaar, P.M.B. van Roosmalen, Image and Video Databases: Restoration, Watermarking and Retrieval, page 14
   Archive film materials are particularly degraded by blotch, scratch, flicker and noise. 2005, Pinar Yolum, Computer and Information Sciences - ISCIS 2005
6. A dark spot on the skin; a pustule.
7. (slang) Blotting paper.

verb

1. (transitive) To mark with blotches.
   1770, Arthur Young, A Six Months Tour through the North of England, London: W. Strahan, Volume 2, p. 258, Upon the whole, the spirit and relief of the figures, with the strength of the colouring, render it a most noble picture; and it is not done in the coarse blotching stile, so common to the pieces which pass under the name of Bassan.
   A straight-edge is placed upon the chalk lines, with the edge next the line slightly raised, and the brush, well filled with colour, drawn along it, just touching the wall, the pressure being never increased, and the brush refilled whenever it is near failing; but great care must be taken that it be not too full, as in that case it will be apt to blotch the line, or drop the colour upon the lower portions of the wall. 1860, W. R. Tymms, chapter 40, in The Art of Illuminating as Practised in Europe from the Earliest Times, London: Day & Son, page 84
   Just beyond were two ancient stone pillars, weather-stained and lichen-blotched bearing upon their summits a shapeless something which had once been the rampant lion of Capus of Birlstone. 1914, Arthur Conan Doyle, The Valley of Fear, Part 1, Chapter 4
   1918, D. H. Lawrence, Parliament Hill in the Evening in New Poems, The houses fade in a melt of mist Blotching the thick, soiled air With reddish places that still resist The Night’s slow care.
   His strong skin was of the Norse snow-fed pallor that no sun ever tanned, no adolescence ever blotched. 1934, Sinclair Lewis, chapter 1, in Work of Art
   Returning on time is crucial, because a late return can be considered a tardy, and too many tardies can blotch an employment record. 2007, Patricia A. Gwartney, The Telephone Interviewer's Handbook
   The only thing you can do in finishing that can't be fixed fairly easily is to blotch the wood with a stain. 2010, Bob Flexner, Flexner on Finishing
   There are some pointers which a hand operating an iron must keep in mind: If a brand is not burned deep enough, it will not peel, and if the iron is too hot, especially when a complicated stamp iron is used, it is pretty sure to blotch the brand. 2013, Fay E. Ward -, The Cowboy at Work
   A slightly incorrect choice of wood for the smoking fire or allowing the smoke to grow too thick can blotch its finish and result in a nearly unusable finished hide. 2015, Henry S. Sharp, Karyn Sharp, Hunting Caribou
2. (intransitive) To develop blotches, to become blotchy.
   1878, Arthur Morecamp (pseudonym of Thomas Pilgrim), Live Boys; or, Charley and Nasho in Texas, Boston: Lee & Shepard, Chapter 17, p. 166, […] when a man is going to drive cattle out of the county he has to put a road-brand on them […] It is generally made of letters or figures, or something that won’t cross lines, because where they cross they are apt to blotch and then it’s hard to tell what the brand is and who the animal belongs to.
   Our waistline will extend a few more inches at least, and our aging skin will blotch and sag. 2008, Mary Jane Warr, Making Sense of Self-Esteem, page 10
   These areas, which also will take longer to dry, are the ones that will blotch when a dye or oil-based finish is applied. 2011, Fine Woodworking Best Finishing Techniques, page 207
   The simpler the brand, the lesser the likelihood that it will blotch and be unsightly and hard to read. 2012, Sue Weaver, Storey's Guide to Raising Miniature Livestock