seed vessel vs pericarp

seed vessel and pericarp both are nouns.

Word	Noun	Adjective	Verb	Adverb
seed vessel	Yes	No	No	No
pericarp	Yes	No	No	No

As nouns, seed vessel and pericarp are synonyms defined as:

seed vessel and pericarp: the ripened and variously modified walls of a plant ovary

seed vessel (noun)	pericarp (noun)
the ripened and variously modified walls of a plant ovary	the ripened and variously modified walls of a plant ovary