Sub-par performance from hunting dog with no lead (5)
I believe the answer is:
eagle
'sub-par performance' is the definition.
I can't tell whether this definition defines the answer.
'hunting dog with no lead' is the wordplay.
'hunting dog' becomes 'beagle' (beagle is a kind of hunting dog).
'with no lead' means to remove the first letter (the letter which leads the word is removed).
'beagle' with its initial letter taken off is 'EAGLE'.
'from' acts as a link.
Can you help me to learn more?
(Other definitions for eagle that I've seen before include "The emblem of the US is bald" , "two strokes fewer?" , "Flyer" , "may be soaring" , "experts are putting more than albatross?" .)