Should have followed them out, I reckoned (9)

I believe the answer is:

methought

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'should have followed them' is the definition.
I can't tell whether this definition defines the answer.

'i reckoned' is the wordplay.
'i' becomes 'me'.
'reckoned' becomes 'thought' ('think' can be a synonym of 'reckon').
'me'+'thought'='METHOUGHT'

'out' is the link.

Can you help me to learn more?

(Other definitions for methought that I've seen before include "The speaker concluded" , "I had the impression" , "In old-fashioned way, I considered" .)

I've seen this clue in the Evening Standard.

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