Etymologically muang/muong/meng comes from various Tai languages meaning "district/region, place, town". Sure Chinese has extensive homophones with different origins and meanings but here, talking about placenames and villages near Tai-speaking areas, there really is no question that it's 勐 here. (From that link that Linguaboy posted of the four pinyins, it will be listed under měng, then 勐.)
Muang (เมือง, ເມືອງ) and Meng (勐) = district, region, place, town
Muang Sing (ເມືອງສີງ) = lion district
Muang Xay (ເມືອງໄຊ) = Xay's district
Muang Mao (မိုင်းမော) = foggy place
Muang Pattaya (เมืองพัทยา) = district of the southwesterly wind
Meng La (勐腊) = tea district
Meng Jiao (勐角) = place to start a family
Meng Mao (勐卯) = foggy place
Muong Thanh (Mường Thanh) = land of God
No need to look to Burmese for etymology of "mae". It has cognates across the whole region meaning "mother" and by extension meaning "river".
mae nam (แม่น้ำ, ແມ່ນ້ຳ, 湄南) = river, sometimes shortened to "mae"
mae (แม่, ແມ່) = mother, (shortened form) river
Mae Nam Khong (ແມ່ນ້ຳຂອງ) = mother river
Mae Lao (แม่ลาว) = mother Lao (= Lao river)
Mae Suai (แม่สรวย) = mother beautiful (= beautiful river)
Me Nam He (湄南河) = river river (湄南 means river in Tai languages, 河 means river in Chinese)
Me Kongk (មេគង្គ) = mother Ganges (Khmer name for Mekong River)
Luang (หลวง, ຫຼວງ) = royal
Luang Prabang (ຫຼວງພະບາງ) = royal image of Buddha
Luang Namtha (ຫຼວງນ້ຳທາ) = royal green river
Khlong Luang (คลองหลวง) = royal canal
San Sai Luang (สันทรายหลวง) = royal sand dune
linguoboy wrote:as in the name of the Lao capital, Luang Prabang or the provincial capital Luang Namtha.
The capital of
Laos is Vientiane.