backslash

Etymology

back + slash, because it is a slash going back against the direction of writing, in contrast to the common slash / (“slash, solidus, oblique, forward slash”).

noun

1. The punctuation mark \.
2. (computing, rare, proscribed) Used erroneously in reference to, or in reading out, the ordinary slash, that is, the punctuation mark /.
   {{quote-book|en|year=2001|author=James T. Bretzke|title=Bibliography on East Asian Religion and Philosophy|publisher=Edwin Mellen Press|isbn=0-7734-7318-1|pageurl=http://books.google.com/books?id=KXwp_xwbHrcC&pg=PA455&dq=backslash|page=455
3. 2010, Lee Vance, The Garden of Betrayal, Random House, published 2011, →ISBN, page 25:
4. 2010, Frank Barnas, Ted White, Broadcast News Writing, Reporting, and Producing, Fifth Edition, Elsevier, →ISBN, page 114:

verb

1. (computing, transitive) To escape (a metacharacter) by prepending a backslash that serves as an escape character, thereby forming an escape sequence.