The old find it disconcerting to associate closely (8)
I believe the answer is:
identify
'associate closely' is the definition.
'identify' can be an answer for 'associate' (identifying is a kind of associating). I'm unsure of the 'closely' bit.
'the old find it disconcerting' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
an anagram of 'find' is 'dnif' which is located in the left over letters.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for identify that I've seen before include "Recognise as specific person or thing" , "Sympathise" , "Diagnose" , "associate" , "Empathise" .)