Is Permanent Resident (PR) called Singaporean?

Permanent Resident (PR) is not a Singaporean. Permanent Residency is not the status of Nationality but Immigration status.

Eg-1: If Permanent Resident is from India, then his nationality is Indian and not Singapore Permanent Resident. But his immigration status in Singapore is Permanent Resident.

Eg-2: If Permanent Resident is from Australia, then his nationality is Australian and not Singapore Permanent Resident. But his immigration status in Singapore is Permanent Resident.