irritation vs arousal

irritation and arousal both are nouns.

Word	Noun	Adjective	Verb	Adverb
irritation	Yes	No	No	No
arousal	Yes	No	No	No

As nouns, arousal is a hypernym of irritation; that is, arousal is a word with a broader meaning than irritation:

irritation (noun)	arousal (noun)
unfriendly behavior that causes anger or resentment	the act of arousing
the act of troubling or annoying someone	mutual sexual fondling prior to sexual intercourse
an uncomfortable feeling of mental painfulness or distress	awakening from sleep
a sudden outburst of anger	a state of heightened physiological activity
the psychological state of being irritated or annoyed
the neural or electrical arousal of an organ or muscle or gland
(pathology) abnormal sensitivity to stimulation