From Longman Dictionary of Contemporary Englishlong johnslong johns /ˈlɒŋ dʒɒnz $ ˈlɒːŋ dʒɑːnz/ noun [plural] DCCwarm underwear with long legs
Examples from the Corpus
long johns• Design: round neck, long sleeve top and long johns, women's and men's designs available.• Layering is vital so good thermal vests and long johns are a must.• At the beginning of the winter I always feel a bit reluctant about working outside until I get my long johns on.• Design: zip front top with lightly padded stand up neck plus long johns.• Also men's long johns and women's sports tights.• It was a hot day, and they took off their uniforms but were wearing long johns.• He was still in his white long johns.Origin long johns (1900-2000) From the male name John 