מָר
From LSJ
Ῥύου δὲ σαυτὸν παντὸς ἐκ φαύλου τρόπου → Ex omni more malefico tete eruas → Bewahre dich vor jeder üblen Lebensart
English (Strong)
or (feminine) marah; from מָרַר; bitter (literally or figuratively); also (as noun) bitterness, or (adverbially) bitterly: + angry, bitter(-ly, -ness), chafed, discontented, X great, heavy.