Yielded, returning personnel before important meeting for major part of body (9)
I believe the answer is:
diaphragm
'major part of body' is the definition.
'yielded returning personnel before important meeting' is the wordplay.
'yielded' becomes 'paid' ('pay' can be a synonym of 'yield').
'returning' is a reversal indicator.
'personnel' becomes 'hr' (Human Resources).
'before' is a charade indicator (letters next to each other).
'important meeting' becomes 'agm' (short for annual general meeting).
'paid' written backwards gives 'diap'.
'diap'+'hr'+'agm'='DIAPHRAGM'
'for' is the link.
(Other definitions for diaphragm that I've seen before include "It separates the thorax from the abdomen" , "Thin dividing membrane" , "Partition between thorax and abdomen" , "Midriff" , "Partitioning membrane" .)