Entry 2 senses · 2 variants Webster, 1913 Sulk /sŭlk/ · IPA /sʌlk/ n. v. i. 01 n. A furrow. 1. A furrow.[Obs.] 02 v. i. To be silently sullen; to be morose or obstinate. 1. To be silently sullen; to be morose or obstinate.