Radiate good time, both endlessly and across the world (6)
I believe the answer is:
global
'across the world' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for global that I've seen before include "Comprehensive" , "all over the place" , "Of the whole world, worldwide" , "Affecting the whole world" , "Universal" .)