From Longman Dictionary of Contemporary Englishdown in the dumpsdown in the dumpsinformalSAD/UNHAPPY very sad and without much interest in life She’s feeling a bit down in the dumps. → dump
Examples from the Corpus
down in the dumps• She supposed she was feeling a bit down in the dumps, apprehensive too about celebrating Christmas Day at the Danbys.• If you're feeling down in the dumps, come over and have a chat.• Mom's kind of down in the dumps at the moment -- why don't you buy her something to cheer her up?• You sound pretty down in the dumps.• But his company is still down in the dumps.• We can't have you down in the dumps like this. 