gepen
גפנ
'gepen' may mean “vine” or specifically “grapevine”. It often occurs in conjunction with yeneb (grapes).
However, in some occurrences it is clearly not a grapevine. 2 Kings 4:39 tells of a 'gepen' that yielded not grapes but rather “strange gourds” that ruined the stew. The word here translated as “gourd” is a hapax legomenon so we can't draw much of a conclusion from that. It should also be noted that there are species of wild grapes that are toxic. On the other hand, the cook in this story “sliced” the fruit, which may indicate something larger than grapes.
Isaiah 7:23 associates 'gepen' with briers and thorns. Grape vines do not have thorns, but thorns are often found on other species of vines, such as blackberry vines or brambles.
Several instances in the book of Ezekiel describe the 'gepen' more like a large tree with strong branches.
LexID 1612