Acute observation from Kelvin hereunder, regularly associated with you (4,3)

'acute observation from kelvin hereunder regularly associated with you' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'acute observation from kelvin hereunder regularly associated with you' is the wordplay.
I cannot quite see how this works, but
'acute' could be 'keen' ('keen' can be a synonym of 'acute') and 'keen' is found in the answer.
'you' could be 'ye' and 'ye' is present in the answer.
A single letter 'e' remains which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?