1. The failure or inability to recognize, acknowledge, or be grateful for the value, effort, or qualities of someone or something
His lack of appreciation for her hard work deeply hurt her feelings.
A falta de apreciação dele pelo trabalho árduo dela a machucou profundamente.
2. Ingratitude or failure to show gratitude
The lack of appreciation shown by the audience was disappointing.
A falta de apreciação demonstrada pelo público foi decepcionante.