Leading pair of lawyers venerated, though losing first brief (7)
I believe the answer is:
laconic
'brief' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
(Other definitions for laconic that I've seen before include "In short" , "without verbosity" , "like a man of few words" , "Terse - can coil (anag)" , "Conical (anag) -- brief and to the point" .)