instillment vs insertion

instillment and insertion both are nouns.

Word	Noun	Adjective	Verb	Adverb
instillment	Yes	No	No	No
insertion	Yes	No	No	No

As nouns, insertion is a hypernym of instillment; that is, insertion is a word with a broader meaning than instillment:

instillment: the introduction of a liquid (by pouring or injection) drop by drop
insertion: the act of putting one thing into another

Other hypernyms of instillment include introduction, intromission.

instillment (noun)	insertion (noun)
the introduction of a liquid (by pouring or injection) drop by drop	the act of putting one thing into another
	a message (spoken or written) that is introduced or inserted