Definition of "Bitter" :
noun: the property of having a harsh unpleasant taste
noun: the taste experience when quinine or coffee is taken into the mouth
noun: English term for a dry sharp-tasting ale with strong flavor of hops (usually on draft)
verb: make bitter
adjective: marked by strong resentment or cynicism
"Bitter about the divorce."
adjective: proceeding from or exhibiting great hostility or animosity
"A bitter struggle."
adjective: expressive of severe grief or regret
"Shed bitter tears."
adjective: causing a sharply painful or stinging sensation; used especially of cold
adjective: harsh or corrosive in tone
adjective: causing a sharp and acrid taste experience
"Quinine is bitter."
adjective: very difficult to accept or bear
"The bitter truth."
adverb: extremely and sharply
"It was bitterly cold."