A Jiva is a human being - body, mind, ego. Along with the Atman, the Jivatman becomes a living human being. Therefore, words can be tricky sometimes, and we have to be careful. People interchange and use Jiva for a person who is alive. But in reality, it is the Jivatman who is alive. The moment the Atman goes and the Jiva is left, it is dead, there is no breath. But basically Jiva is meant for that. Sometimes, people use the word Jiva even for animals, but the true meaning of Jiva in spirituality is the body, mind and ego complex in which the Atman dwells.