From Longman Dictionary of Contemporary Englishmumpsmumps /mʌmps/ noun [uncountable] (also the mumps) MIan infectious illness which makes your neck swell and become painfulGRAMMAR: Singular or plural verb?Mumps is followed by a singular verb: Mumps is quite serious if you get it as an adult.
Examples from the Corpus
mumps• There are lots of viruses; for example, one kind causes chickenpox, another mumps and other colds.• I did get the usual childhood ailments, though, such as mumps, measles and chicken-pox.• Scarlet fever, mumps, chicken pox, and whooping cough floated in the air.• The vaccine is used to immunise children against measles, mumps and rubella.• All doses of Hib, measles, mumps, rubella, and varicella must be given on or after the first birthday.• An epidemic of measles, mumps or rubella is now possible.• Think of it like the mumps.Origin mumps (1500-1600) mump “expression made by twisting the mouth” ((16-17 centuries)) 