Pronunciation enPR: sŭlʹən, IPA (key): /ˈsʌlən/ Audio (US)(file) Hyphenation: sul‧len Adjective Positive sullen Comparative sullener Superlative sullenest A sullen person is someone who does not want to smile or be nice to others. Synonym: sulkyWikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads