Unusually, Egham ____ includes rowing, skiffing and punting races (7)
I believe the answer is:
regatta
'unusually egham includes rowing skiffing and punting' is the definition.
I can't judge whether this definition defines the answer.
'races' is the wordplay.
I cannot quite understand how this works, but
'races' could be 'tt' (Isle of Man Tourist Trophy races) and 'tt' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for regatta that I've seen before include "Boat racing event" , "Boat race-meeting" , "Sailing races" , "Boating event" , "Display of boats" .)