Posh Home Secretary left card (6)
I believe the answer is:
palace
'posh home' is the definition.
(a fancy house)
'secretary left card' is the wordplay.
'secretary' becomes 'PA' (abbreviation for personal assistant).
'left' becomes 'L' (common abbreviation).
'card' becomes 'ace' (ace is a type of playing card).
'pa'+'l'+'ace'='PALACE'
(Other definitions for palace that I've seen before include "Royal mansion" , "Locality round a monarch's official residence" , "very nice house" , "Regal mansion" , "Stately mansion" .)