Second daughter holding in brown stomach (5)
I believe the answer is:
stand
'stomach' is the definition.
(I know that stomach can be written as stand)
'second daughter holding in brown' is the wordplay.
'second' becomes 's' (common abbreviation).
'daughter' becomes 'd' (genealogical abbreviation).
'holding in' means one lot of letters goes inside another.
'brown' becomes 'tan' (tan is a kind of brown).
's'+'d'='sd'
'sd' placed around 'tan' is 'STAND'.
(Other definitions for stand that I've seen before include "Seek election; attitude" , "group of trees" , "Remain upright" , "Be erect" , "Decline to interfere when one should?" .)