instillation vs instilment

instillation and instilment both are nouns.

Word	Noun	Adjective	Verb	Adverb
instillation	Yes	No	No	No
instilment	Yes	No	No	No

As nouns, instillation and instilment are synonyms defined as:

instillation and instilment: the introduction of a liquid (by pouring or injection) drop by drop

Other synonyms of instillation include instillment.

instillation (noun)	instilment (noun)
the introduction of a liquid (by pouring or injection) drop by drop	the introduction of a liquid (by pouring or injection) drop by drop
a liquid that is instilled drop by drop