The last week or so I've been spending a lot of time with Harry Shorto's A Dictionary of Modern Spoken Mon (1962). With its companion volume, A Dictionary of the Mon Inscriptions (1971), it makes for some interesting reading.
Personally, I don't know a lot about Mon, but historically it has had a lot of influence on Thai, which mostly goes unrecognized. The Mon were in Southeast Asia more than two millennia before the arrival of the Tai (ancestors of the Thai, Lao, Shan, etc.) from an area of what is now southern China.
Yesterday I noticed a connection, but of a different kind. It's a semantic similarity between modern spoken Thai and modern spoken Mon.
In Mon, just as in Thai, the word for 'cashew' comes from the word for 'mango'. The Thai word for 'mango' is มะม่วง /mamûaŋ/ (from หมาก /màak/ + ม่วง /mûaŋ/); the Mon word is /krɜk/. Now, obviously there's no common origin between those two words.
The mango/cashew connection presumably derives from their similar shape. The cashew nut is native to Brazil, and was spread throughout the world by the Portuguese, who were among the earliest Europeans in Southeast Asia. The cashew took well to the tropical climes of South and Southeast Asia. Today, Vietnam is the largest producer of cashews in the world, with more than four times the annual output of Brazil; India produces more than double that of Brazil.
(Interesting side note: In areas of Thailand's south, the cashew is called กาหยู /kaayǔu/, which, like English 'cashew', comes from the Portuguese word acajú, and ultimately from the indigenous Tupi word acajuba.)
The standard Thai word for 'cashew' is มะม่วงหิมพานต์ /mamûaŋ hǐmmaphaan/ 'Himmaphan mango'. The Thai word หิมพานต์ /hǐmmaphaan/ is from Himavanta, the name of the forest in Hindu mythology which lies at the base of Mount Meru.
The Mon word for 'cashew' is /krɜk soiŋkhɜ̀/. The phonology obscures it a bit, but the second word is from Sanskrit /siṃhala/ (corresponding to Thai สิงหล /sǐŋhǒn/). It is the Mon word for Ceylon/Sinhala, which was partially ruled by the Portuguese in the 17th Century, before the Dutch moved in, and then the British, before modern independence under the name Sri Lanka.
So for Thais, a cashew is a 'Himavanta mango', while for Mon it's a 'Sinhala mango'. The Mon name presumably comes from the nut's place of origin from the Mon perspective. I'm not sure how the Thai word came to refer to a mythical forest in the Jataka tales. Does anyone else have any insight into that?
Regardless, it's an interesting semantic similarity. I wonder if there was any influence in one direction or the other.