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]

The Free On-line Dictionary of Computing (19 January 2023):

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.