undreamt vs undreamed

undreamt and undreamed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
undreamt	No	Yes	No	No
undreamed	No	Yes	No	No

As adjectives, undreamt and undreamed are synonyms defined as:

Other synonyms of undreamt include undreamed of, undreamt of, unimagined.

undreamt (adjective)	undreamed (adjective)
not imagined even in a dream	not imagined even in a dream