'Bitter' in the Bible

Husbands, love your wives, and be not bitter against them.

Doth a fountain send forth at the same place sweet water and bitter?

But if ye have bitter envying and strife in your hearts, glory not, and lie not against the truth.

And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.

And I went unto the angel, and said unto him, Give me the little book. And he said unto me, Take it, and eat it up; and it shall make thy belly bitter, but it shall be in thy mouth sweet as honey.

And I took the little book out of the angel's hand, and ate it up; and it was in my mouth sweet as honey: and as soon as I had eaten it, my belly was bitter.