make bitter

Why be so hard of heart and by thy rude taunts make bitter the food he must receive from our hands?

He began to make bitter allusions to "clever fellows who stick at nothing to get on."

Why did he make bitter to me the little sweetness that was dearer to me than my life?

Eugnie and I no longer spoke to each other except to make bitter, sneering remarks; most of the time we said nothing.

Marco advanced towards him, and began to make bitter complaints against Jeremiah.