A form of morah; trouble -- bitterness.
see HEBREW morah
H4787. morrah
[מָרָּה] noun feminine bitterness (on form see Ges§ 22, 5 R); — construct נַפְשׁוֺ מָרַּת יוֺדֵעַ לֵב Proverbs 14:10 the heart knoweth the bitterness of its soul (its own misery).