- clobber (v.) 1941, British air force slang, probably related to bombing; possibly echoic. Related: Clobbered; clobbering. In late 19c. British slang the word principally had to do with clothing, e.g. clobber (n.) "clothes," (v.) "to dress smartly;" clobber up "to patch old clothes for reuse."
Etymology dictionary. 2014.