Semitontine \Sem`i*ton*tine"\, a. (LIfe Insurance) Lit., half-tontine; -- used to designate a form of tontine life insurance. See {Tontine insurance}. -- {Sem`i*ton*tine"}, n. Semitontine \Sem`i*ton*tine"\, a. (LIfe Insurance) Lit., half-tontine; -- used to designate a form of tontine life insurance. See {Tontine insurance}. -- {Sem`i*ton*tine"}, n.