The Collaborative International Dictionary of English v.0.48:

Liar \Li"ar\ (l[imac]"[~e]r), n. [OE. liere. See Lie to
   falsify.]
   A person who knowingly utters falsehood; one who lies.
   [1913 Webster]

WordNet (r) 3.0 (2006):

liar
    n 1: a person who has lied or who lies repeatedly [syn: liar,
         prevaricator] [ant: square shooter, straight arrow,
         straight shooter]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "liar":
   Ananias, Baron Munchausen, Father of Lies, Satan,
   Sir John Mandeville, consummate liar, dirty liar, equivocator,
   fabricator, fabulist, false witness, falsifier, fibber, fibster,
   habitual liar, mythomaniac, palterer, pathological liar, perjurer,
   prevaricator, pseudologist, pseudologue, spinner of yarns,
   storyteller, teller of tales, yarn spinner, yarner



The Free On-line Dictionary of Computing (30 December 2018):

MIT Scheme
C-Scheme
Edwin
Liar

    (Previously "C-Scheme") A Scheme implementation
   by the MIT Scheme Team (Chris Hanson, Jim Miller, Bill
   Rozas, and many others) with a rich set of utilities,  a
   compiler called Liar and an editor called Edwin.

   MIT Scheme includes an interpreter, large run-time
   library, Emacs macros, native-code compiler, emacs-like
   editor, and a source-level debugger.

   MIT Scheme conforms fully with R4RS and almost with the
   IEEE Scheme standard.  It runs on Motorola 68000:
   HP9000, Sun-3, NeXT; MIPS: Decstation, Sony, SGI;
   HP-PA: 600, 700, 800; VAX: Ultrix, BSD, DEC Alpha:
   OSF; Intel i386: MS-DOS, MS Windows, and various other
   Unix systems.

   See also: LAP, Schematik, Scode.

   (http://gnu.org/software/mit-scheme/).

   Usenet newsgroup: news:comp.lang.scheme.c.

   Mailing list: mit-scheme-announce@gnu.org (cross-posted to
   news).

   E-mail:  (maintainers).

   (2003-08-14)


The Devil's Dictionary (1881-1906):

LIAR, n.  A lawyer with a roving commission.