From Longman Dictionary of Contemporary Englishvacvac /væk/ noun [countable usually singular] British English informalSEC a university vacation1(3)
Examples from the Corpus
vac• I met him during the summer vac.• I also use the vac in the garden, collecting leaves, grass and hedge clippings.• I know that I am not meant to vac up the spiders, just their cobwebs.Origin vac (1900-2000) vacuum 