زقم
Attested forms : ٱلزَّقُّومِ 2 · زَقُّومٍۢ 1
Core meaning
Proper noun of a tree of the Fire. The text ties it to no known tree and defines it by what it does: it comes out at the root of the Blaze and becomes a food that boils in the bellies. The translation keeps the name: "Zaqqoum".
Uses
شَجَرَةُ ٱلزَّقُّوم, شَجَرٍ مِّن زَقُّومٍ → "the tree of Zaqqoum" : the food of those who deny, set against the welcome of the Garden.
Evidence from the text
All three uses describe the same tree by its effects. In 37:62 it is set against "a better welcome", then described: "it is a tree that comes out at the root of the Blaze, whose spathes resemble the heads of Diverters" (37:64); God has made it "a trial for the wrongdoers" (37:63). In 44:43, "like molten metal, it boils in the bellies as boiling water boils" (44:45). In 56:52, the astray are told they will "fill your bellies with it, and drink on top of it boiling water" (56:52). The name is not translated: what the text says of it is enough to define it.
See also
شجر (the tree) · جحم (the Blaze)