The Collaborative International Dictionary of English v.0.48:

Mumps \Mumps\, n. [Prov. E. mump to be sulky. Cf. Mump,
   Mumble, and Mum.]
   1. pl. Sullenness; silent displeasure; the sulks. --Skinner.
      [1913 Webster]

   2. [Prob. so called from the patient's appearance.] (Med.) A
      specific infectious febrile disorder characterized by a
      nonsuppurative inflammation of the parotid glands, and
      sometimes causing inflammation of the testes or ovaries;
      also called epidemic parotitis or infectious
      parotitis. It is caused by infection with a
      paramyxovirus.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

mumps
    n 1: an acute contagious viral disease characterized by fever
         and by swelling of the parotid glands [syn: mumps,
         epidemic parotitis]

Moby Thesaurus II by Grady Ward, 1.0:

144 Moby Thesaurus words for "mumps":
   African lethargy, Asiatic cholera, Chagres fever, German measles,
   Haverhill fever, acute articular rheumatism, ague, alkali disease,
   amebiasis, amebic dysentery, anthrax, bacillary dysentery,
   bastard measles, black death, black fever, blackwater fever, blahs,
   blue devils, blues, breakbone fever, brucellosis, bubonic plague,
   cachectic fever, cerebral rheumatism, chicken pox, cholera, cowpox,
   dandy fever, deer fly fever, dengue, dengue fever, diphtheria,
   dismals, dods, doldrums, dolefuls, dorts, dumdum fever, dumps,
   dysentery, elephantiasis, encephalitis lethargica, enteric fever,
   erysipelas, famine fever, five-day fever, flu, frambesia, frumps,
   glandular fever, grippe, grumps, hansenosis, hepatitis, herpes,
   herpes simplex, herpes zoster, histoplasmosis, hookworm,
   hydrophobia, infantile paralysis, infectious mononucleosis,
   inflammatory rheumatism, influenza, jail fever, jungle rot,
   kala azar, kissing disease, lepra, leprosy, leptospirosis, loa loa,
   loaiasis, lockjaw, madness, malaria, malarial fever, marsh fever,
   measles, megrims, meningitis, milzbrand, mopes, mulligrubs,
   ornithosis, osteomyelitis, paratyphoid fever, parotitis,
   parrot fever, pertussis, pneumonia, polio, poliomyelitis,
   polyarthritis rheumatism, ponos, pouts, psittacosis, rabbit fever,
   rabies, rat-bite fever, relapsing fever, rheumatic fever,
   rickettsialpox, ringworm, rubella, rubeola, scarlatina,
   scarlet fever, schistosomiasis, septic sore throat, shingles,
   sleeping sickness, sleepy sickness, smallpox, snail fever,
   splenic fever, spotted fever, strep throat, sulks, sullens,
   swamp fever, tetanus, thrush, tinea, trench fever, trench mouth,
   tuberculosis, tularemia, typhoid, typhoid fever, typhus,
   typhus fever, undulant fever, vaccinia, varicella, variola,
   venereal disease, viral dysentery, whooping cough, yaws,
   yellow fever, yellow jack, zona, zoster



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

MUMPS
       Massachusetts general hospital Utility Multi-Programming System


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

MUMPS
       Multi-User Multi-Programming System ??? (OS, DEC)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

MUMPS
       MUMPS Development Committee (org., MUMPS)


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

MUMPS

    (Or "M") Massachusetts General Hospital Utility
   Multi-Programming System.

   A programming language with extensive tools for the support of
   database management systems.  MUMPS was originally used for
   medical records and is now widely used where multiple users
   access the same databases simultaneously, e.g. banks, stock
   exchanges, travel agencies, hospitals.

   Early MUMPS implementations for PDP-11 and IBM PC were
   complete operating systems, as well as programming
   languages, but current-day implementations usually run under a
   normal host operating system.

   A MUMPS program hardly ever explicitly performs low-level
   operations such as opening a file - there are programming
   constructs in the language that will do so implicitly, and
   most MUMPS programmers are not even aware of the operating
   system activity that MUMPS performs.

   Syntactically MUMPS has only one data-type: strings.
   Semantically, the language has many data-types: text strings,
   binary strings, floating point values, integer values,
   Boolean values.  Interpretation of strings is done inside
   functions, or implicitly while applying mathematical
   operators.  Since many operations involve only moving data
   from one location to another, it is faster to just move
   uninterpreted strings.  Of course, when a value is used
   multiple times in the context of arithmetical operations,
   optimised implementations will typically save the numerical
   value of the string.

   MUMPS was designed for portability.  Currently, it is possible
   to share the same MUMPS database between radically different
   architectures, because all values are stored as text strings.
   The worst an implementation may have to do is swap pairs of
   bytes.  Such multi-CPU databases are actually in use, some
   offices share databases between VAX, DEC Alpha, SUN,
   IBM PC and HP workstations.

   Versions of MUMPS are available on practically all hardware,
   from the smallest (IBM PC, Apple Macintosh, Acorn
   Archimedes), to the largest mainframe.  MSM (Micronetics
   Standard MUMPS) runs on IBM PC RT and R6000; DSM (Digital
   Standard Mumps) on the PDP-11, VAX, DEC Alpha, and
   Windows-NT; Datatree MUMPS from InterSystems runs on
   IBM PC; and MGlobal MUMPS on the Macintosh.
   Multi-platform versions include M/SQL, available from
   InterSystems, PFCS  and MSM.

   Greystone Technologies' GT/M runs on VAX and DEC Alpha.
   This is a compiler whereas the others are interpreters.
   GT/SQL is their SQL pre-processor.

   ISO standard 11756 (1991).  ANSI standard: "MUMPS Language
   Standard", X11.1 (1977, 1984, 1990, 1995?).

   The MUMPS User's Group was the M Technology Association.

   Usenet newsgroups: news:comp.lang.mumps.

   (2003-06-04)