It hurts American with boring visit to travel covertly (4,4)
I believe the answer is:
stow away
'travel covertly' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'it hurts american with boring visit' is the wordplay.
'it hurts' becomes 'ow' (exclamation of pain).
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'with' becomes 'w' (abbreviation).
'boring' means one lot of letters goes inside another (some letters must 'bore' a hole into other letters).
'visit' becomes 'stay' (I've seen this in another clue).
'ow'+'a'+'w'='owaw'
'owaw' inserted into 'stay' is 'STOW AWAY'.
'to' acts as a link.
Can you help me to learn more?
(Another definition for stow away that I've seen is " Sneak on board".)