Boxing in Jack and King with lead of ten (5,3)

'boxing' is the definition.
Both the answer and definition are singular nouns.
Maybe there's an association between them I don't understand?

'in jack and king with lead of ten' is the wordplay.
'in jack' becomes 'nob' (term in the card game cribbage. I am not sure about the 'in' bit.).
'and' means one lot of letters go next to another.
'king' becomes 'lear' (Shakespeare's King Lear).
'with' is a charade indicator (letters next to each other).
'lead of' says to take the initial letters (I've seen 'leading' mean this).
The first letter of 'ten' is 't'.
'nob'+'lear'+'t'='NOBLE ART'

Can you help me to learn more?