Excellent T-shirt on fellow at fair? (3-6)
I believe the answer is:
top-flight
'excellent' is the definition.
(I've seen this before)
'shirt on fellow at fair?' is the wordplay.
'shirt' becomes 'top' (I've seen this in another clue).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'fellow' becomes 'F' (abbreviation - of a society etc.).
'at' is a charade indicator (letters next to each other).
'fair?' becomes 'light' (as in fair hair).
'top'+'f'+'light'='TOP-FLIGHT'
't' acts as a link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for top-flight that I've seen before include "Superior" , "Of the highest class" , "Highest level" , "Excellent -- best possible" .)