Pronunciation IPA (key): /ˈlɛsn̩/ Audio (US)(file) Audio (UK)(file) Hyphenation: les‧son Homophone: lessen Noun Singular lesson Plural lessons (countable) A lesson is a time when something is taught. Synonym: class The Math lesson starts at 5:12.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads