Well-built dam (7)
I believe the answer is:
staunch
This clue might be a double definition.
'well-built' is the first definition.
(thesaurus)
'dam' is the second definition.
Although both the answer and definition are verbs in their base form, I can't understand how one could define the other.
Can you help me to learn more?
(Other definitions for staunch that I've seen before include "Arrest" , "Reliable" , "Stout" , "Stay - faithful" , "Loyal; restrict (a flow of blood)" .)