A boy my lord ordered to bring a drink (6,4)
I believe the answer is:
bloody mary
'a drink' is the definition.
(Bloody Mary is an example)
'a boy my lord ordered' is the wordplay.
'ordered' is an anagram indicator.
'a'+'boy'+'my'+'lord'='aboymylord'
'aboymylord' is an anagram of 'BLOODY MARY'.
'to bring' acts as a link.
(Other definitions for bloody mary that I've seen before include "Tomato juice and vodka" , "Queen regarded unfavourably" , "The Red Queen" , "Nickname of Henry VIII's first daughter" , "killing Queen?" .)