learning from experience; repenting; improving one's nature
Almost exclusively used in the set phrase 性懲りもなく (しょうこりもなく), meaning 'without learning one's lesson' or 'incorrigibly'. The standalone noun is rare.
See also: 性懲りもなく (しょうこりもなく)
He repeated the same mistake again without learning his lesson.
He goes back to gambling, never learning.
Standard kanji spelling for this noun, though the word itself is almost always used in the phrase 性懲りもなく.
Kana spelling is common in everyday writing, especially when the kanji are considered difficult or obscure.
Compound of 性 (しょう, 'nature, disposition') and 懲り (こり, 'learning from experience', from 懲りる). The exact historical derivation is uncertain, but the word is now fossilized in the adverbial phrase 性懲りもなく.