Whelk is a common name that is applied to various kinds of sea snail, many of which have historically been used, or are still used, by humans for food.
Although a number of whelks are relatively large and are in the family Buccinidae (the true whelks), the word whelk is also applied to some other marinegastropodmolluscspecies within several families of sea snails that are not very closely related.
The common name "whelk" is also spelled welk or even wilks. The word originated from the Proto-Germanic root "weluka", which may come from the Proto-Indo-European root "wel-", meaning to turn or revolve. 
The species, genera and families referred to by this common name vary a great deal from one geographic area to another.