'Bitterness' in the Bible

For I see that you are in the gall of bitterness and in the bondage of iniquity."

"whose mouth is full of cursing and bitterness."

Let all bitterness, wrath, anger, outcry, and slander, be put away from you, with all malice.

looking carefully lest there be any man who falls short of the grace of God; lest any root of bitterness springing up trouble you, and many be defiled by it;