Submission having broken knee in dining room (8)
I believe the answer is:
meekness
'submission' is the definition.
(I know that submission can be written as meekness)
'broken knee in dining room' is the wordplay.
'broken' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'dining room' becomes 'mess' (mess is a kind of dining room).
'knee' is an anagram of 'eekn'.
'eekn' going within 'mess' is 'MEEKNESS'.
'having' is the link.
(Other definitions for meekness that I've seen before include "submission" , "Submissive humility" , "Submissive quality" , "Submissive nature" , "Formally inform" .)