Nianfo is a term commonly seen in Pure Land Buddhism. In the context of Pure Land practice, it generally refers to the repetition of the name of Amitābha. It is a translation of Sanskrit buddhānusmṛti.
What does Nembutsu mean in Buddhism?
It is the BASIC meaning. For the person who is seeking salvation, the Nembutsu means "Save me, Amida Buddha." It means that the seeker is opening her/himself to Amida's saving Light and Compassion. It is the seeker responding to Amida's Call and opening him/herself to Amida Buddha's Other Power.
What is the nembutsu chant?
To practice nembutsu, chant 'Namo Amida Bu' for five minutes, once or twice a day. That's it. You can either say the words, as you can hear here, or use a tune which you can hear here.