Order brother to get early start for card game (5)
I believe the answer is:
ombre
'for card game' is the definition.
(I've seen this before)
'order brother to get early start' is the wordplay.
'order' becomes 'om' (Order of Merit).
'brother' becomes 'br' (abbreviation in titles of monks).
'to get' means one lot of letters go next to another.
'start' indicates taking the first letters.
The first letter of 'early' is 'e'.
'om'+'br'+'e'='OMBRE'
(Other definitions for ombre that I've seen before include "Tricky game" , "Three-player card game" , "Old card game (from the Spanish for "man")" , "Card game for three" , "solo player" .)