cranky vs irritable

cranky and irritable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
cranky	No	Yes	No	No
irritable	No	Yes	No	No

As adjectives, cranky and irritable are synonyms defined as:

Other synonyms of cranky include fractious, nettlesome, peckish, peevish, pettish, petulant, scratchy, techy, testy, tetchy.

cranky (adjective)	irritable (adjective)
easily irritated or annoyed	easily irritated or annoyed
(used of boats) inclined to heel over easily under sail	capable of responding to stimuli
	abnormally sensitive to a stimulus