An idiomatic Mandarin Chinese greeting, literally meaning "Have you eaten to fullness?"
It's common in agricultural-based economies, where people's fortunes are subject to the vagaries of natural phenomena and famine is a real and regular possiblity, for social conventions to coalesce around food and eating. Ni chi bao le ma is a more formal greeting than the casual Ni hao. The correct/polite response is "Chi bao le" meaning "I have eaten to fullness."
The tones: Ni(2) chi(4) bao(3) le ma.