grim vs unforgiving

grim and unforgiving both are adjectives.

Word	Noun	Adjective	Verb	Adverb
grim	No	Yes	No	No
unforgiving	No	Yes	No	No

As adjectives, grim and unforgiving are synonyms defined as:

grim and unforgiving: not to be placated or appeased or moved by entreaty

Other synonyms of grim include inexorable, relentless, stern, unappeasable, unrelenting.

grim (adjective)	unforgiving (adjective)
shockingly repellent; inspiring horror	unwilling or unable to forgive or show mercy
filled with melancholy and despondency	not to be placated or appeased or moved by entreaty
causing dejection
not to be placated or appeased or moved by entreaty
harshly ironic or sinister
harshly uninviting or formidable in manner or appearance