IVMac3:4 :ܡܪܝܪܘܬ ܝܨܪܐ ܠܐ ܡ݂ܨܐ ܐܢܫ ܕܡܢܗ ܢܢܟܪܐ‏ : a person is unable to remove bitterness of temperament from himself
See the entire entry for marrīrū, marrīrūṯā n.f. bitterness