American quietly infiltrates splinter groups and has a sense of foreboding (8)
I believe the answer is:
suspects
'has a sense of foreboding' is the definition.
I can't judge whether this definition defines the answer.
'american quietly infiltrates splinter groups' is the wordplay.
'american' becomes 'US' (United States).
'quietly' becomes 'p' (p for piano and quiet).
'infiltrates' indicates putting letters inside.
'splinter groups' becomes 'sects' (I've seen this in another clue).
'us'+'p'='usp'
'usp' inserted into 'sects' is 'SUSPECTS'.
'and' is the link.
Can you help me to learn more?
(Other definitions for suspects that I've seen before include "Thinks likely" , "Believes, supposes" , "Believes to be guilty but without proof" , "Believes something might be true" , "Distrusts" .)