American TV channel? (4)
I believe the answer is:
tube
This might be a double definition.
'american tv' is the first definition.
'tube' can be an answer for 'tv' (I've seen this in another clue). I'm not sure about the 'american' bit.
'channel?' is the second definition.
(tube is a kind of channel)
Can you help me to learn more?
(Other definitions for tube that I've seen before include "Cylindrical hollow conduit" , "Transport system" , "appearing tinny?" , "TV" , "Can of beer (colloquial)" .)