From Longman Dictionary of Contemporary Englisheverything but the kitchen sinkeverything but the kitchen sinkinformalEQUIPMENT all the equipment that you need and also a lot of things that you do not need – used humorously I think we’ve packed everything but the kitchen sink! → everything
Examples from the Corpus
everything but the kitchen sink• Burglars broke in and took everything but the kitchen sink.• When my parents come to stay with us, they bring everything but the kitchen sink!• Aunt Hortense: Babsy Hepworth's bronzes, everything but the kitchen sink.everything but the kitchen sinkeverything but the kitchen sinkhumorousLOT/LARGE NUMBER OR AMOUNT used when someone has brought too many things with them → kitchenExamples from the Corpus
everything but the kitchen sink• Aunt Hortense: Babsy Hepworth's bronzes, everything but the kitchen sink. 