Material very little seen in the borders of Thailand (5)
I believe the answer is:
tweed
'material' is the definition.
(tweed is a kind of material)
'very little seen in the borders of thailand' is the wordplay.
'very little' becomes 'wee'.
'seen in' means one lot of letters goes inside another.
'the borders of' means to remove the middle letters.
'thailand' with its middle taken out is 'td'.
'wee' going into 'td' is 'TWEED'.
(Other definitions for tweed that I've seen before include "Fabric; river" , "River; rough cloth" , "Scottish/English river" , "Flower on border" , "Sort of jacket" .)