The chowder in chowderhead is neither New England nor Manhattan (though one could speculate that a chowderhead has either type of clam chowder for brains). Chowderhead is a mispronunciation of jolterhead, a derivative of the 16th-century insult jolt head. Before being extended to a thickheaded person (i.e., a blockhead), the term jolt head was used literally for a large, heavy head. The etymology of jolt head is obscure; the term is likely connected somehow to the jolt that means "an abrupt jerky blow or movement," but the exact nature of the connection is not known.
Examples of chowderhead in a Sentence
instantly concluded his new son-in-law was a chowderhead