Sulky/ˈsʌlki/ Definition 1 of 2Pro Tip 1/3Negative Emotion Sulky often conveys a childish or immature way of showing unhappiness. Stop being so sulky; we can’t always win. Pro Tip 2/3Nonverbal Cue Sulky behavior can be expressed through body language, without words. His sulky slump in the chair showed his disappointment. Pro Tip 3/3Not Polite Being sulky might be considered rude or disrespectful in social or formal situations. Her sulky behavior at the dinner table was noticeable.