clunker (n.)youdaoicibaDictYouDict[clunker 词源字典]
"anything inferior," 1940s, agent noun from clunk (v.), probably in imitation of the sounds made by old machinery. Specific sense of "old car" was in use by 1951 (clunk in the sense "old worn-out machine" is from 1940s).[clunker etymology, clunker origin, 英语词源]