Beach in France welcomes first uprising over pestilence (6)
I believe the answer is:
plague
'pestilence' is the definition.
(I know that plague is a type of pestilence)
'beach in france welcomes first uprising' is the wordplay.
'beach in france' becomes 'plage' (I've seen this in another clue).
'welcomes' indicates putting letters inside (in sense of 'invites in').
'first uprising' becomes 'u' (1st letter of 'uprising').
'plage' going around 'u' is 'PLAGUE'.
'over' is the link.
(Other definitions for plague that I've seen before include "Contagious disease with a high mortality rate" , "Fast-spreading disease" , "Contagious disease with a high death rate" , "large scale affliction" , "dog" .)