sulk

Etymology 1

Back-formation from sulky, of uncertain origin. Probably from Middle English *sulke, *solke (attested in solcennesse (“idleness; laziness”), from Old English āsolcennys (“idleness; slothfulness; sluggishness; laziness”), from āsolcen (“sulky, languid”), from past participle of Old English āseolcan (“be slow; be weak or slothful; languish”), from Proto-Germanic *selkaną (“to fall in drops; dribble; droop”), from Proto-Indo-European *sélǵ-o-nom, from *selǵ- (“to let go, send”). Cognate with several Indo-Iranian words deriving from Proto-Indo-Iranian *sarȷ́- (such as Sanskrit सृजति (sṛjáti), सर्जति (sarjati), सर्जन (sárjana), सृक (sṛká)), possibly Hittite 𒊭𒀠𒀝𒍣 (ša-al-ak-zi /⁠šalkzi⁠/, “knead, mix”), although the semantic connection is weak.

verb

1. (intransitive) To express ill humor or offence by remaining sullenly silent or withdrawn.

noun

1. A state of sulking.
   He thanks our miserable Liberal agent, an unbeliever called Donald Somebody, see the caption, who since the court's arrival on his territory has retired into a fuming sulk from which he has only tonight emerged. 1986, John le Carré, A Perfect Spy
   "[…] home during the holidays," said the Doctor with a good-humoured laugh, "but a fit of the sulks is no very uncommon thing for him;" and then he added,[…] 2012, Harriet S. Caswell, Walter Harland Or, Memories of the Past, tredition
   Leo has been in a sulk all morning.
2. (in the plural, preceded by definite article) A fit of sulking; a sulking mood.
   The Puddin', who had got the sulks over Sam's remark that fifteen goes of steak and kidney were enough for any self-respecting man, protested against the singing, which, he said, disturbed his gravy. 1918, Norman Lindsay, The Magic Pudding, page 82
3. A person who sulks
   Don't be such a sulk, Leo!

Etymology 2

Latin sulcus.

noun

1. A furrow.