A peninsula in SE Asia separating the Indian Ocean from the South China Sea. It extends approximately 1,100 km (700 miles) southwards from the Isthmus of Kra and comprises the southern part of Thailand and the whole of West Malaysia.
Definition of Malay Peninsula in US English:
Malay Peninsula
proper noun
A peninsula in Southeast Asia that separates the Indian Ocean from the South China Sea. It extends approximately 700 miles (1,100 km) south from the Isthmus of Kra and comprises the southern part of Thailand and all of Malaya (West Malaysia).