Apathy is a loss of interest in or indifference to things a person would normally think are important or pleasant. Lack of motivation or enthusiasm may be seen in apathy. And apathy may be a symptom of depression.
The word "apathy" comes from a Greek word that means "loss of feeling." Someone who is apathetic, for example, might be uninterested when a fire/rescue truck pulls up at his neighbor and friend's house, or not become excited when her daughter calls to announce a pregnancy.