metonymic vs metonymical

metonymic and metonymical both are adjectives.

Word	Noun	Adjective	Verb	Adverb
metonymic	No	Yes	No	No
metonymical	No	Yes	No	No

As adjectives, metonymic and metonymical are synonyms defined as:

metonymic and metonymical: using the name of one thing for that of another with which it is closely associated

metonymic (adjective)	metonymical (adjective)
using the name of one thing for that of another with which it is closely associated	using the name of one thing for that of another with which it is closely associated