I cannot go because of infection (9)
I believe the answer is:
contagion
'infection' is the definition.
(I know that infection can be written as contagion)
'i cannot go because' is the wordplay.
'i cannot go' anagrams to 'CONTAGION'.
However, I am not sure how the anagram is indicated.
'of' is the link.
Can you help me to learn more?
(Other definitions for contagion that I've seen before include "Infection" , "cause of widespread ill-feeling" , "Communication of disease by close contact" , "Cognation (anag.)" .)