15th cent. meaning "group of clouds." The modern sense is first recorded in the 18th cent. Borrowed from Italian gruppo 'id.,' itself borrowed from Old Occitan grupo, which in turn was borrowed from a Germanic source.
Ultimately from Proto-Germanic *kruppa- "body (of things)." Derived from Proto-Indo-European *gru̯bh-néh2- "to crawl" from a sense of crumpling up.
Old Norse kroppr "body," Old High German kropf "goiter," Old English crop "sprout" (English crop)