Extinguish last of blazes by dam (7)
I believe the answer is:
smother
'extinguish' is the definition.
(I've seen this before)
'last of blazes by dam' is the wordplay.
'last of blazes' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'by' means one lot of letters go next to another.
'dam' becomes 'mother' (I've seen this before).
's'+'mother'='SMOTHER'
Can you help me to learn more?
(Other definitions for smother that I've seen before include "Prevent from breathing" , "Put out" , "Extinguish (fire) by covering it" , "blanket" , "2 (anag)" .)