FROM STRONG’S HEBREW DICTIONARY (1890)

Strong’s Hebrew Dictionary (1890) — public domain, printed whole.

marah maw-raw' — a primitive root; to be (causatively, make) bitter (or unpleasant); (figuratively) to rebel (or resist; causatively, to provoke):--bitter, change, be disobedient, disobey, grievously, provocation, provoke(-ing), (be) rebel (against, -lious).