uncertain vs incertain

uncertain and incertain both are adjectives.

Word	Noun	Adjective	Verb	Adverb
uncertain	No	Yes	No	No
incertain	No	Yes	No	No

As adjectives, uncertain and incertain are synonyms defined as:

uncertain and incertain: lacking or indicating lack of confidence or assurance

Other synonyms of uncertain include unsure.

uncertain (adjective)	incertain (adjective)
not established beyond doubt; still undecided or unknown	lacking or indicating lack of confidence or assurance
lacking or indicating lack of confidence or assurance
not certain to occur; not inevitable
not established or confirmed
ambiguous (especially in the negative)
not consistent or dependable
subject to change