(transitive, intransitive) To repeatedly remind or complain to (someone) in an annoying way, often about insignificant or unnecessary matters. / To bother with persistent thoughts or memories.

Someone or something that nags. / A repeated complaint or reminder. / A persistent, bothersome thought or worry.

Misspelling of knack.

(Britain) immediately, without delay

(transitive) to attach with nails / (idiomatic, transitive) to make something (e.g. a decision or plan) firm or certain

(idiomatic) To identify something exactly; to arrive at exactly the right answer.

(idiomatic) An event that increases the likelihood of or causes further failure.

Lacking worldly experience, wisdom, or judgement; unsophisticated. / Not having been exposed to something.

A naive person; a greenhorn.

(US, slang, rare) To do something that is impossible or very difficult, with connotations of pointlessness.