testament vs testimonial

testament and testimonial both are nouns.

Word	Noun	Adjective	Verb	Adverb
testament	Yes	No	No	No
testimonial	Yes	Yes	No	No

As nouns, testimonial is a hypernym of testament; that is, testimonial is a word with a broader meaning than testament:

Other hypernyms of testament include testimony.

testament (noun)	testimonial (noun)
a profession of belief	something that recommends (or expresses commendation of) a person or thing as worthy or desirable
a legal document declaring a person's wishes regarding the disposal of their property when they die	something given or done as an expression of esteem
strong evidence for something	something that serves as evidence

testament (adjective)	testimonial (adjective)
	of or relating to or constituting testimony
	expressing admiration or appreciation