Wimp and weed - terribly British (5)
I believe the answer is:
dweeb
'wimp' is the definition.
(I've seen this in another clue)
'weed terribly british' is the wordplay.
'terribly' indicates an anagram.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'weed' anagrammed gives 'dwee'.
'dwee'+'b'='DWEEB'
'and' is the link.
(Other definitions for dweeb that I've seen before include "Nerd - wimp" , "(US) idiot" , "Fool" , "Antisocial guy" , "misfit" .)