Notice unusual power given Yard (4)
I believe the answer is:
espy
'notice' is the definition.
(I've seen this before)
'unusual power given yard' is the wordplay.
'unusual power' becomes 'esp' (I've seen this in another clue).
'given' means one lot of letters go next to another.
'yard' becomes 'y' (abbreviation).
'esp'+'y'='ESPY'
(Other definitions for espy that I've seen before include "Watch" , "Perceive" , "Make out at a distance" , "Spot at a distance" , "Spot, notice" .)