1. A sub-cortical structure of the brain. It is part of the telencephalon, but retains close functional ties with the subthalamus – both of which are part of the extrapyramidal motor system. (wikipedia.org)
2. (Anatomy) the inner part of the lenticular nucleus of the brain. (wiktionary.org)
3. The median portion of the lentiform nucleus—called also pallidum. (merriam-webster.com)
Word Origin: From Latin pallidus “pale, colorless,” from root of pallere” be pale.