Run aground on the London thoroughfare (6)
I believe the answer is:
strand
'run aground' is the definition.
(thesaurus)
'on the london thoroughfare' is the wordplay.
'on' is a charade indicator (letters next to each other).
'the london' becomes 'rand' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'thoroughfare' becomes 'st' (I've seen this in other clues).
'rand' put after 'st' is 'STRAND'.
Can you help me to learn more?
(Other definitions for strand that I've seen before include "Bit of wire, say" , "Beach or shore" , "Thread - London street" , "Ringlet or stretch of beach" , "Drive aground on shore" .)