I've had the question before, and the answer I used is "not very tall." Seeing that euphemism means to not be offensive.
In the first sentence, the definition of channel is to express his feelings through a particular behavior or action.
In the second sentence, a channel is a means or a medium of communication, or the passage of information.
In the third sentence, a channel means a passage, a waterway, or a navigable course through a body of water.
Examples are comma, colon, semi-colon, Dash, parentheses,
