Unsteady pig's foot leaving first run on yard (7)
I believe the answer is:
tottery
'unsteady' is the definition.
(similar in meaning)
'pig's foot leaving first run on yard' is the wordplay.
'pig's foot' becomes 'trotter' (trotter means a pig's foot eaten as food).
'leaving' suggests deleting specific letters.
'first run' becomes 'r' (1st letter of 'run').
'on' is a charade indicator (letters next to each other).
'yard' becomes 'y' (abbreviation).
'trotter' with 'r' taken away is 'totter'.
'totter'+'y'='TOTTERY'
(Other definitions for tottery that I've seen before include "Moving insecurely" , "Moving unsteadily" , "Unsteady (on one's feet)" , "Frail" , "rocking" .)