High street name in dictionary (6)
I believe the answer is:
stoned
'high' is the definition.
(I've seen this before)
'street name in dictionary' is the wordplay.
'street' becomes 'st'.
'name' becomes 'n' (common abbreviation e.g. on forms).
'in' is an insertion indicator.
'dictionary' becomes 'oed' (Oxford English Dictionary).
'n' placed within 'oed' is 'oned'.
'st'+'oned'='STONED'
(Other definitions for stoned that I've seen before include "Doesn't (anag) - drunk" , "High on a drug" , "Incapable from drug-taking" , "Like Olive perhaps" , "Executed in Biblical way, or slangily drunk" .)