Starts to bring in monarch for the last frame (4)
I believe the answer is:
bier
'frame' is the definition.
(I have seen 'Funereal frame' mean 'bier' so perhaps 'frame' could also mean 'bier')
'starts to bring in monarch for the last' is the wordplay.
'starts to' suggests taking the first letters.
'monarch' becomes 'r' (abbreviation for rex, king in Latin).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'last' suggests the final letters.
The initial letters of 'bring in' is 'bi'.
The last letter of 'the' is 'e'.
'r' after 'e' is 'er'.
'bi'+'er'='BIER'
(Other definitions for bier that I've seen before include "Frame for carrying the dead" , "Moving support for a coffin" , "Support for a coffin before burial" , "stiff drink in Munich festival" , "Brie (anag.)" .)