Thousands round hotel area head for interior shade (5)
I believe the answer is:
khaki
'shade' is the definition.
(I have seen 'Uniform shade' mean 'khaki' so perhaps 'shade' could also mean 'khaki')
'thousands round hotel area head for interior' is the wordplay.
'thousands' becomes 'kk' (I am not sure about this - if you are sure you should believe this answer much more).
'round' indicates putting letters inside.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'area' becomes 'a' (maths abbreviation).
'head for' suggests taking the first letters.
The first letter of 'interior' is 'i'.
'h'+'a'='ha'
'kk' placed around 'ha' is 'khak'.
'khak'+'i'='KHAKI'
Can you help me to learn more?
(Other definitions for khaki that I've seen before include "'Colour, often used for military uniforms (5)'" , "Military clothes" , "Uniform shade" , "Army dress material" , "Dullish brown colour" .)