bastardism ? Obs.|ˈbɑːstədɪz(ə)m, -æ-| [f. bastard n. + -ism.] The condition of a bastard, illegitimacy, bastardy. 1589Almond for P. 38 Is Christ descended of bastardisme or no, as you gaue out in the pulpyt.1753Scots Mag. Oct. 489/1 We ought to remove..the incapacities of bastardism.