ostium vs womb

ostium

noun
  • Any of the small openings or pores in a sponge. 

  • A small opening or orifice, as in a body organ or passage. 

  • The mouth of a river. 

womb

noun
  • Any cavity containing and enveloping anything. 

  • In female mammals, the organ in which the young are conceived and grow until birth; the uterus. 

  • A place where something is made or formed. 

How often have the words ostium and womb occurred in a corpus of books? (source: Google Ngram Viewer )