Intensity in United game almost exploded (9)
I believe the answer is:
magnitude
'intensity' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for magnitude that I've seen before include "Relative importance" , "Dimensions" , "(A star's) brightness" , "Eating mud (anag.)" , "Largeness or size" .)