inlet vs ostium

inlet

noun
  • A passage that leads into a cavity. 

  • A body of water let into a coast, such as a bay, cove, fjord or estuary. 

verb
  • To let in; admit. 

  • To carve the wooden stock of a firearm so as to position the metal components in it. 

  • To insert; inlay. 

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. 

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