A meths product well known to be nonflammable (6)
I believe the answer is:
thames
'be nonflammable' is the definition.
I can't tell whether this defines the answer.
'a meths product well known' is the wordplay.
'a meths' anagrams to 'THAMES'.
Though, I am not clear how this is indicated.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for thames that I've seen before include "capital banker" , "London's river (6)" , "Longest English river" , "Sam the river" , "The Ma's in the river" .)