The story
From mammillary (“resembling a breast or nipple”) + body.
Etymology from Wiktionary, CC BY-SA 4.0.
mammillary body
Today it means: One of a pair of small round bodies, located on the undersurface of the human brain, that act as a relay for impulses coming from the amygdalae and hippocampi to the thalamus, and (as part of the diencephalon) form part of the limbic system. Full definition →