The term CAMP SACK is composed of three words: COT (3 letters), COTS (4 letters), and SAD (3 letters). COT is an abbreviation for cotter, which is a metal pin or bolt used to secure two parts together. COTS is an abbreviation for cots, which are portable beds that are often used in camping. SAD is an acronym for sleeping bag, which is a large, insulated bag used for sleeping outdoors. Together, these three words form the term CAMP SACK, which refers to a combination of cotter, cots, and sleeping bags used for camping.