Blow up a dam? (5)
I believe the answer is:
blast
'blow up' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for blast that I've seen before include "Shoot" , "Damn - explosion" , "slate" , "Blow up with explosives" , "Sudden, strong current of air" .)