ill-tempered vs grumpy

ill-tempered and grumpy both are adjectives.

Word	Noun	Adjective	Verb	Adverb
ill-tempered	No	Yes	No	No
grumpy	No	Yes	No	No

As adjectives, ill-tempered and grumpy are synonyms defined as:

Other synonyms of ill-tempered include bad-tempered, crabbed, crabby, cross, fussy, grouchy.

ill-tempered (adjective)	grumpy (adjective)
annoyed and irritable	annoyed and irritable