The lower of the two grey nuclei of the corpus striatum.The lentiform nucleus is present only on the left side of the illustration....
Fibers of the optic and auditory radiations are interposed between the lentiform nucleus above and the temporal horn of the lateral ventricle below.
The putamen of the lentiform nucleus has been removed to expose the more medially situated globus pallidus, which is so named because it is paler than the putamen.
Origin
Early 18th century: lentiform from Latin lens, lent- 'lentil' + -iform.