urokinasePronunciation: /ˌjʊərə(ʊ)ˈkʌɪneɪz/Definition of urokinase noun [mass noun] Biochemistry an enzyme produced in the kidneys which promotes the conversion of plasminogen to plasmin and can be used to dissolve blood clots. urokinase in other Oxford dictionaries Definition of urokinase in the US English dictionary