corpus lu·te·um 
(ltē-əm)
(ltē-əm)n. pl. corpora lu·te·a (ltē-ə)
A yellow, progesterone-secreting mass of cells that forms from an ovarian follicle after the release of a mature egg. Also called yellow body.
[New Latin corpus lūteum : Latin corpus, body + Latin lūteum, neuter of lūteus, yellow.]