My son hired out body armour (7)

I believe the answer is:

corslet

I'm a little stuck... Click here to teach me more about this clue!

'body armour' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?

'my son hired out' is the wordplay.
'my' becomes 'cor' (both are expressions of surprise).
'son' becomes 's' (genealogical abbreviation for son).
'hired out' becomes 'let'.
'cor'+'s'+'let'='CORSLET'

Can you help me to learn more?

(Another definition for corslet that I've seen is " Piece of armour".)

I've seen this clue in The Independent.

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