Make clear that engineer can slumber (10)

I believe the answer is:

unscramble

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'make clear' is the definition.
'unscramble' can be an answer for 'clear' (thesaurus). I am not sure about the 'make' bit.

'engineer can slumber' is the wordplay.
'engineer' indicates an anagram.
'can'+'slumber'='canslumber'
'canslumber' with letters rearranged gives 'UNSCRAMBLE'.

'that' acts as a link.

Can you help me to learn more?

(Other definitions for unscramble that I've seen before include "Restore to readability" , "Restore to a readable state" .)

I've seen this clue in The Guardian.

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