New King James Version (NKJV)
“15 The ‘rod’ (Lamad: instruct(ion), teacher(ing)) and rebuke give wisdom, But a child left to himself brings shame to his mother.”
Strong’s Hebrew Lexicon:
Rod: 3925 lamad law-mad’ a primitive root; properly, to goad, i.e. (by implication) to teach (the rod being an Oriental incentive):(un-) accustomed, X diligently, expert, instruct, learn, skilful, teach(-er, – ing).