Lighthearted (4)
'lighthearted' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for glad that I've seen before include "Made up" , "Happy, cheerful" , "bright?" , "These rags are dressy clothes - happy?" , "Not sorry" .)
(Other definitions for jokey that I've seen before include "ready with gag" , "Inclined to quip" , "Amusing" .)