1.a path over which electrical signals can pass;

a channel is typically what you rent from a telephone company

2.a passage for water (or other fluids) to flow through;

the fields were crossed with irrigation channels

3.a long narrow furrow cut either by a natural process (such as erosion) or by a tool (as e.g. a groove in a phonograph record)

4.a deep and relatively narrow body of water (as in a river or a harbor or a strait linking two larger bodies) that allows the best passage for vessels;

the ship went aground in the channel

5.(often plural) a means of communication or access;

it must go through official channels

6.a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance;

the tear duct was obstructed

7.a television station and its programs;

a satellite TV channel

8.a way of selling a company's product either directly or via distributors;

possible distribution channels are wholesalers or small retailers or retail chains or direct mailers or your own stores