An Etymological Dictionary of the German Language/Annotated/Hummer
Hummer, masculine, ‘lobster,’ Modern High German only, from the equivalent Low German (Danish and Swedish) hummer; the final source is Old Icelandic humarr, masculine, ‘lobster’; compare Greek κάμαρος, κάμμαρος, ‘a kind of crab,’ although the occurrence of the same names of fishes in several Aryan languages is usually very rare. In English a different word is used — Anglo-Saxon loppestre, feminine, English lobster.