Secret greeting before daughter is taken into private room (6)
I believe the answer is:
hidden
'secret' is the definition.
(I've seen this before)
'greeting before daughter is taken into private room' is the wordplay.
'greeting' becomes 'hi' (hi is a kind of greeting).
'before' is a charade indicator (letters next to each other).
'daughter' becomes 'd'.
'is taken into' indicates putting letters inside.
'private room' becomes 'den' (a secret room or location).
'd' put into 'den' is 'dden'.
'hi'+'dden'='HIDDEN'
(Other definitions for hidden that I've seen before include "Concealed, recondite" , "Consealed or secret" , "Concealed, having been put away secretly" , "Covert, obscured" , "not obvious" .)