Torrential movements of French toboggans (7)
I believe the answer is:
deluges
'torrential movements' is the definition.
The answer and definition can be both types of natural phenomena as well as being plural nouns.
Maybe you can see an association between them that I can't see?
'of french toboggans' is the wordplay.
'of french' becomes 'de' ('of' in French).
'toboggans' becomes 'luges' ('luge' can be a synonym of 'toboggan').
'de'+'luges'='DELUGES'
Can you help me to learn more?
(Other definitions for deluges that I've seen before include "Heavy downpours of rain" , "swamps" .)