Pia cannot be spelled together, there is no such spelling in Chinese Pinyin.
Pia can actually be said to be the homophone of "pa". Piapia is an onomatopoeia, which actually means "papa". With the accent of Northeastern dialect, it becomes piapia. But there is actually no such pronunciation.
Similar pinyin are:
Piě [piě]:
1. Throw it flat: throw away the brick. Skimming grenades. Put what I said in the morning to the back of my mind.
2. Slanted: He has splayed feet, which are pointed outward when he walks.
farewell [bié]:
1. Separation: farewell. Parting remembrance. Reunion after a long absence. Farewell, my alma mater.
2. In addition: others. Another name. There are ulterior motives.
3. Turn; transform: She turned her head away. This person's temper can't be controlled for a while.