Originally Posted by
N830MH
Yes, there's a lounge near concourse E. After you crossed the security. You can go into the lounge.
JetBlue does not have any lounges. AFAIK there is no Priority Pass lounge in T3 or T4 (concourses E, F, or G) at FLL. There is a Priority Pass restaurant in T4 but most credit card memberships do not include those anymore.
N830MH is correct - there is an Escape Lounge near the E concourse of T3, but they do not accept Priority Pass. You need to either have an Amex Platinum, or a Delta SkyMiles Reserve Amex

Looks like you learn something new every day.
-J.