Drunken comedian lacking energy and wandering (7)
I believe the answer is:
nomadic
'wandering' is the definition.
(synonyms)
'drunken comedian lacking energy' is the wordplay.
'drunken' indicates anagramming the letters.
'lacking' indicates named letters should be taken away.
'energy' becomes 'e' (physics symbol as in E=mc2).
'comedian' with 'e' removed is 'comdian'.
'comdian' with letters rearranged gives 'NOMADIC'.
'and' is the link.
(Other definitions for nomadic that I've seen before include "Lacking fixed home" , "vagrant" , "Itinerant" , "Roaming" , "Peripatetic" .)