fundament

1. a. The buttocks.
   b. The anus.
2. The natural features of a land surface unaltered by humans.
3. A foundation, as of a building.
4. An underlying theoretical basis or principle: “All neighbor states … must revise … their policy fundaments” (C.L. Sulzberger).

Origin:

Origin: Middle English foundement

Origin: , from Old French fondement

Origin: , from Latin fundāmentum

Origin: , from fundāre, to lay the foundation

Origin: , from fundus, bottom