Channel (noun)

1. A means of communication or access to something.
2. A long, narrow strip of water connecting two larger bodies of water.
3. A specific frequency or band of frequencies used for transmitting a signal.

Origin:

Middle english: from old french chanel, from latin canalis "channel, pipe", from canna "reed, pipe".

Examples:

1. The company uses social media as a channel to reach customers.
2. The water flowed through the channel.
3. The channel was blocked by debris.
4. The signal was transmitted on a specific channel.
5. The company had multiple channels of communication with its clients.