Before noon, first person would be seen in the thick of it (4)
I believe the answer is:
amid
'in the thick of it' is the definition.
(I've seen this in another clue)
'before noon first person would' is the wordplay.
'before noon' becomes 'AM' (as in AM on a clock).
'first person' becomes 'I' (first-person pronoun).
'would' becomes 'd' (I've seen this in other clues).
'am'+'i'+'d'='AMID'
'be seen' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for amid that I've seen before include "Surrounded by" , "Within" , "In the course of" , "In the centre of" , "Amongst" .)