Ran off in dread, perhaps (7)

I believe the answer is:

drained

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'ran off' is the definition.
'drained' can be an answer for 'ran' (draining is a kind of running). I am unsure of the 'off' bit.

'in dread perhaps' is the wordplay.
'perhaps' indicates an anagram.
'in'+'dread'='indread'
'indread' with letters rearranged gives 'DRAINED'.

Can you help me to learn more?

(Other definitions for drained that I've seen before include "Tired" , "spent" , "empty" , "Deprived of strength" , "Emptied of liquid" .)

I've seen this clue in the Evening Standard.

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