Dutch Etymology 1 From zwemmen + -ster. Pronunciation IPA(key): /ˈzʋɛmstər/ Noun zwemster f (plural zwemsters, diminutive zwemstertje n) (female) swimmer Etymology 2 From zwemmen + ster. Pronunciation IPA(key): /ˈzʋɛmstɛr/ Noun zwemster m (plural zwemsterren, diminutive zwemsterretje n) swimming star (successful swimmer) Wikiwand - on Seamless Wikipedia browsing. On steroids.