Skinny has hired out a piece of armour (8)
I believe the answer is:
gauntlet
'armour' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'skinny has hired out a piece' is the wordplay.
'skinny has' becomes 'gaunt' (I am not sure about this - if you are sure you should believe this answer much more).
'hired' becomes 'lent'.
'out' indicates named letters should be taken away.
'a piece' becomes 'n' (abbreviation for Knight in chess notation).
'lent' with 'n' removed is 'let'.
'gaunt'+'let'='GAUNTLET'
'of' is the link.
Can you help me to learn more?
(Other definitions for gauntlet that I've seen before include "Long-sleeved glove" , "that may be punishing for runner" , "It may be thrown down or run" , "What might represent a challenge" , "Punishment to be run - heavy glove" .)