Quarrel about nuclear risk (4,3)
I believe the answer is:
fall out
This clue might be a double definition.
'quarrel' is the first definition.
(I know that fall out is a type of quarrel)
'nuclear risk' is the second definition.
Although both the answer and definition are verbs in their base form, I cannot see how they can define each other.
'about' acts as a link.
Can you help me to learn more?
(Other definitions for fall out that I've seen before include "Happen" , "disagree" , "Quarrel - leave the ranks" , "Radioactive pollution" .)