Neighbor of Thailand (4)
I believe the answer is:
laos
'neighbor of thailand' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for laos that I've seen before include "Republic of southeast Asia" , "part of Asia" , "Country of Indo-China, capital Vientiane" , "Republic in southeastern Asia" , "Country between Thailand/Vietnam" .)