From The Collaborative International Dictionary of English v.0.48 :
parser \pars"er\, n. One who parses. [1913 Webster]From WordNet (r) 3.0 (2006) :
parser n 1: a computer program that divides code up into functional components; "compilers must parse source code in order to translate it into object code"From The Free On-line Dictionary of Computing (30 December 2018) :
parser parse parsed parsingAn algorithm or program to determine the syntactic structure of ("to parse") a sentence or string of symbols in some language. A parser normally takes as input a sequence of tokens output by a lexical analyser. It may produce some kind of abstract syntax tree as output. A parser may be produced automatically from a grammar by a parser generator such as yacc. A parser is normally part of some larger program, like a compiler, which takes the output of the parser and attempts to extract meaning from it in some way, e.g. translating it into another language. (2009-06-26)