Squat in E London joint: filthy place all round (6)
I believe the answer is:
stocky
'squat' is the definition.
(synonyms)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for stocky that I've seen before include "Strongly-built" , "Short and solidly built" , "Heavily built" , "Thickset" , "Heavily-built" .)