Word parts sun + burn Pronunciation (US) IPA (key): /ˈsʌnbɝn/ (UK) IPA (key): /ˈsʌnbɜːn/ Audio (UK)(file) Hyphenation: sun‧burn Noun Singular sunburn Plural sunburns (countable & uncountable) Sunburn is a burn on the skin caused by excess and long exposure to the sun's rays.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads