hummock (n.)youdaoicibaDictYouDict[hummock 词源字典]
"knoll, hillock," 1550s, originally nautical, "conical small hill on a seacoast," of obscure origin, though second element is diminutive suffix -ock. In Florida, where the local form is hammock, it means a clump of hardwood trees on a knoll in a swamp or on a key.[hummock etymology, hummock origin, 英语词源]