Fundament
Fundament , noun
[Old English fundament, fundement, fondement, Old French fundement, fondement, French fondement, from Latin fundamentum foundation, from fundare to lay the bottom, to found, from fundus bottom. See Fund.]
1.
Foundation. [Obsolete] — Chaucer
2.
(Anatomy) The part of the body on which one sits; the buttocks; specifically (Anatomy), the anus. — Hume