The phrase "taking heart" implies the feeling of being encouraged and hopeful. Antonyms for this phrase would include words that convey disheartenment or discouragement such as despair, defeat, hopelessness, and resignation. These words indicate a lack of hope or confidence in the future. Instead of taking heart, one might lose heart, meaning to become discouraged, dispirited or depressed. Other antonyms for taking heart could include feeling pessimistic, uninspired, bleak, or apathetic. Losing heart can cause one to feel demotivated and disengaged from life, but it is important to remember that there are always other ways to find hope and positivity in difficult times.