A brick from ace with merchandise left (1,4,5)

'a brick' is the definition.
(both can mean a dependable person)

'ace with merchandise left' is the wordplay.
'ace' becomes 'a'.
'with' is a charade indicator (letters next to each other).
'merchandise' becomes 'goods' (goods can mean merchandise or wares).
'left' becomes 'port' (left side of a ship - opposite of starboard).
'a'+'goods'+'port'='A GOOD SPORT'

'from' is the link.