introduction vs intromission

introduction and intromission both are nouns.

Word	Noun	Adjective	Verb	Adverb
introduction	Yes	No	No	No
intromission	Yes	No	No	No

As nouns, introduction and intromission are synonyms defined as:

introduction and intromission: the act of putting one thing into another

Other synonyms of introduction include insertion.

introduction (noun)	intromission (noun)
the act of putting one thing into another	the act of putting one thing into another
the act of beginning something new
the act of starting something for the first time; introducing something new
the first section of a communication
formally making a person known to another or to the public
a basic or elementary instructional text
a new proposal