ostium

Etymology
Borrowed from.

Noun

 * 1) A small opening or orifice, as in a body organ or passage.
 * 2) Any of the small openings or pores in a sponge.
 * 3) The mouth of a river.

Etymology
Formed from or cognate with.

Noun

 * 1) door
 * 2) entrance
 * 3) estuary
 * 4) mouth (of a river)

Descendants

 * Padanian:
 * Padanian:
 * Padanian:
 * Padanian:
 * Padanian: