Sat on this brick? (6)
I believe the answer is:
friend
'this brick?' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for friend that I've seen before include "Comrade for finder" , "Quaker - pal" , "Close associate" , "Pal or buddy" , "Pal, amigo" .)