Adder circling right foot (7)
I believe the answer is:
trotter
'foot' is the definition.
(I know that trotter is a type of foot)
'adder circling right' is the wordplay.
I cannot really see how this works, but
'right' could be 'r' (common abbreviation) and 'r' is present in the answer.
The remaining letters 'totter' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for trotter that I've seen before include "Harnessed mount" , "horse getting sulky, say" , "Briskly moving horse - pig's foot" , "Steady horse; pig's foot" , "Edible foot?" .)