One expecting Bottom here in play (6-2-2)
I believe the answer is:
mother-to-be
'one expecting' is the definition.
'bottom here in play' is the subsidiary indication.
'in play' indicates an anagram.
'bottom'+'here'='bottomhere'
'bottomhere' with letters rearranged gives 'mothertobe'.
(Other definitions for mother-to-be that I've seen before include "One expecting a baby" , "She's expecting" , "Expecting woman?" .)