Drunken pair connected more than usually liable to mishap (8-5)
I believe the answer is:
accident-prone
'more than usually liable to mishap' is the definition.
(likely to have accidents)
'drunken pair connected' is the wordplay.
'drunken' indicates anagramming the letters.
'pair'+'connected'='pairconnected'
'pairconnected' anagrammed gives 'ACCIDENT-PRONE'.
(Other definitions for accident-prone that I've seen before include "Involved in unusually frequent mishaps" , "Given to mishaps" , "Liable to have mishaps" , "With a Tendency to suffer misfortune" , "Susceptible to mishap" .)