Definitions of pia:

• noun:   perennial herb of East Indies to Polynesia and Australia; cultivated for its large edible root yielding Otaheite arrowroot starch
• name:  A female given name (rare: 1 in 50000 females; popularity rank in the U.S.: #2192)
• name:  A surname (very rare: popularity rank in the U.S.: #25227)