Sultry individual without an ID (5)

I believe the answer is:

humid

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'sultry' is the definition.
(synonyms)

'individual without an id' is the wordplay.
'individual' becomes 'humi' (I can't explain this - if you can you should believe this answer much more).
'without' suggests deleting specific letters.
'an' becomes 'i' (Roman numeral for one).
'id' with 'i' removed is 'd'.
'humi'+'d'='HUMID'

Can you help me to learn more?

(Other definitions for humid that I've seen before include "Clammy" , "Rather wet" , "Dank" , "Muggy" , "Moist (atmosphere)" .)

I've seen this clue in The Telegraph.

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