I think it is pronounced 'oss'
I study bones and stuff and generally 'os' means opening as in 'os coxae' the hip bones that have a hole at the bottom.
( Anthropos Was making beer on, Mon 25 May 2009, 16:57, archived)

Pah. I study physics
and has such knows no information about the female body at all
( Master Of Turnips. Only gays and morons believe in ghosts., Mon 25 May 2009, 16:59, archived)

Physics is a real man's science anyway!

( Anthropos Was making beer on, Mon 25 May 2009, 17:00, archived)