I have been wondering about the origin of the word 'Mat Salleh' as it does not appear to have any particular link to the Malay Language.
One of the most plausible origins relates to the Portuguese presence in Malacca.
The Portuguese took Malacca in 1511 and their sailors used the port as a naval cum supply base, for Portugal's colonial ambitions in Asia. Many of the Portuguese sailors, after a long sea voyage from Europe, would run riot in Malacca - getting drunk, singing loudly and making a lot of noise. The local folk in Malacca used to refer to them as, "Mad Sailors" and this apparently got shortened to "Mat Salleh”!
It certainly sounds as though it could be true!
The Portuguese controlled Malacca for 130 years, until they were kicked out by the Dutch.
Interestingly, there is still a Portuguese settlement in Malacca called “Perkampungan Portugis”, where many of the Portuguese customs are still retained.
They also speak a “creole type” language, which is a mixture of Portuguese and Malay.
Some Malay words have their origin in Portuguese, for example:
Malay Portuguese
Almari (Wardrobe) Armario
Baldi (Pail) Balde
Boneka (Doll) Boneca
Keju (Cheese) Queijo
Kereta (Car) Carreta
and many more.