Star out last is dispersed in thick cloud (11)

I believe the answer is:

altostratus

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'thick cloud' is the definition.
'altostratus' can be an answer for 'cloud' (altostratus is a kind of cloud). I'm unsure of the 'thick' bit.

'star out last is dispersed' is the wordplay.
'is dispersed' indicates an anagram.
'star'+'out'+'last'='staroutlast'
'staroutlast' with letters rearranged gives 'ALTOSTRATUS'.

'in' acts as a link.

Can you help me to learn more?

(Other definitions for altostratus that I've seen before include "Cloud forming a uniform layer" , "Sky feature" .)

I've seen this clue in The Times.

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