Extend personal support to include November subsequently (8)

I believe the answer is:

lengthen

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'extend' is the definition.
(I've seen this in another clue)

'personal support to include november subsequently' is the wordplay.
'personal support' becomes 'leg' (leg is a kind of support. I am not sure about the 'personal' bit.).
'to include' means one lot of letters goes inside another.
'november' becomes 'N' (phonetic alphabet: alpha, bravo, charlie etc.).
'subsequently' becomes 'then' (synonyms).
'leg' going around 'n' is 'leng'.
'leng'+'then'='LENGTHEN'

Can you help me to learn more?

(Other definitions for lengthen that I've seen before include "Stretch" , "Elongate" , "Protract" , "Prolong" , "Make or become longer" .)

I've seen this clue in The Guardian.

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