Strong's #4844: mror (pronounced mer-ore')

or mrowr {mer-ore'}; from 4843; a bitter herb:-- bitter(-ness).

Brown-Driver-Briggs Hebrew Lexicon:

/

merôr

1) bitter thing, bitter herb, bitterness

Part of Speech: noun masculine

Relation: from H4843

Usage:

This word is used 3 times:

 

Exodus 12:8: "with fire, and unleavened bread; and with bitter herbs they shall eat"
Numbers 9:11: "they shall keep it, and eat it with unleavened bread and bitter"
Lamentations 3:15: "He hath filled me with bitterness, he hath made me drunken with wormwood."