I firmly believe that Epicurean philosophy should be easily explained without having to re-define a common word.
And you're on exactly the same page as Cicero, and you'll want to do more reading from Torquatus and decide whether Cicero's position or Torquatus' makes the most sense!
This is Cicero speaking to Torquatus in Book 2 of On Ends:
Cicero, Marcus Tullius, On Ends - De Finibus Bonorum Et Malorum : Cicero : Free Download, Borrow, and Streaming : Internet Archive
Cicero - De Finibus - translated by H. Rackham
archive.org