OB vs presentation

OB and presentation both are nouns.

Word	Noun	Adjective	Verb	Adverb
OB	Yes	No	No	No
presentation	Yes	No	No	No

OB (noun)	presentation (noun)
the branch of medicine dealing with childbirth and care of the mother	a show or display; the act of presenting something to sight or view
	the activity of formally presenting something (as a prize or reward)
	a visual representation of something
	(obstetrics) position of the fetus in the uterus relative to the birth canal
	the act of making something publicly available; presenting news or other information by broadcasting or printing it
	the act of presenting a proposal
	formally making a person known to another or to the public