### Clue: Taken as 23, serving also to separate sons and daughters (10)
### Answer: UNDERSTOOD 
 ### Explanation: Definition: Taken as 23
 UNDER(serving;subservient to) + [ TOO(also) **contained in**(to separate) S,D(abbrevs. respectively for "sons" and "daughters") ].
Defn: Taken as read(the answer to 23 across)