Showing irritation can be expressed in two ways: peevishly and pained. PEEVISH is an adjective that means 'bad-tempered or irritable, ' while pained is an adjective that means 'showing or expressing physical or mental suffering.' Both words are used to describe someone who is showing signs of irritation, but the difference between them is that PEEVISH implies a more sustained level of irritation, while pained implies a more acute level of irritation.