Gabbing aimlessly about physics concept (3,4)
I believe the answer is:
big bang
'physics concept' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'gabbing aimlessly' is the wordplay.
'aimlessly' is an anagram indicator (the letters rearranged chaotically or aimlessly).
'gabbing' anagrammed gives 'BIG BANG'.
'about' acts as a link.
Can you help me to learn more?
(Other definitions for big bang that I've seen before include "Theoretical first ever moment?" , "beginning to matter?" , "Stock Exchange reform" , "Theoretically, the first thing" , "Theoretical origin of the universe" .)