Naughty means behaving badly in a small, childish way. A naughty child, that was naughty, the naughty step.
It is used almost entirely of children and of pets, and affectionately even then — real wrongdoing gets a stronger word. The naughty step is the British name for a place a small child is sent to calm down. Applied to adults it usually means mildly rude or indulgent: a naughty joke, a naughty second slice. Note that naughty once meant genuinely wicked, and the softening is one of the clearest examples in English of a word losing its teeth.
1adjectivenaughtyBehaving badly in a small, childish way.
“He was naughty all afternoon and charming by six.”
synonyms: mischievous, badly behaved
2adjectivemildlyMildly rude or indulgent.
“A second helping felt naughty and she had it anyway.”
naughty is a mild misbehaviour.
Also accepted in games: mischievous
Middle English noughti comes from nought, meaning nothing — a naughty person was a person who had nothing, then a person who was worth nothing, then a wicked one, and finally a slightly badly behaved child.
Middle English
noughti
English, today
naughty
Built from
From late Middle English noughti, naughty (“evil, immoral, wicked”), from nought (“evil, immoral”) + -ī̆. Analysable as naught + y.
Etymology from Wiktionary, CC BY-SA