mourning vs grief-stricken

mourning is a noun but grief-stricken is not a noun.

Word	Noun	Adjective	Verb	Adverb
mourning	Yes	Yes	No	No
grief-stricken	No	Yes	No	No

As adjectives, mourning and grief-stricken are synonyms defined as:

Other synonyms of mourning include bereaved, bereft, grieving, sorrowing.

mourning (noun)	grief-stricken (noun)
the passionate and demonstrative activity of expressing grief
state of sorrow over the death or departure of a loved one

mourning (adjective)	grief-stricken (adjective)
sorrowful through loss or deprivation	sorrowful through loss or deprivation