Pulau Ujong or Singapore Island is the main island

Island

An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

 of the island country of Singapore

Singapore

Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

. It forms the majority of the island country in terms of area and population. It was the easiest reference to the Singapore Island as anyone travelling from the Straits of Malacca to the South China Sea

South China Sea

The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around...

 or vice versa would have to pass the island, hence giving it the name. Like Johor

Johor

Johor is a Malaysian state, located in the southern portion of Peninsular Malaysia. It is one of the most developed states in Malaysia. The state capital city and royal city of Johor is Johor Bahru, formerly known as Tanjung Puteri...

's old name, ujong tanah meaning "Land's End", the island was known better by the Orang laut

Orang Laut

The Orang Laut, or Bajau Laut are a group of Malay people living in the Riau Islands of Indonesia. It also may refer to any Malay origin people living on coastal islands, including those of Andaman Sea islands in Thailand and Burma, commonly known as Moken.-Etymology:The Malay term orang laut...

as Pulau Ujong literally meaning "End Island". The early Chinese reference to P'u Luo Chung corresponds to the Malay reference known as Pualau Juong. In the 18th century, the island was known as Pulau Panjang (Long Island).