penis

The external reproductive organ of males. It is composed of a mass of erectile tissue enclosed in three cylindrical fibrous compartments. Two of the three compartments, the corpus cavernosa, are placed side-by-side along the upper part of the organ. The third compartment below, the corpus spongiosum, houses the urethra.

Definition from MeSH (D010413), National Library of Medicine, read 2026-09-23. NLM revises MeSH; this copy may not reflect its current record.