To play a podcast on your Apple Watch without headphones, you'll need to use the device's built-in speaker. Here's how:

1. Open the Podcasts app on your Apple Watch.
2. Use the Digital Crown or your finger to scroll through your list of podcasts.
3. Tap on the podcast you want to listen to.
4. Once the podcast episode's page opens, tap on the Play button.

The podcast will start playing directly from your Apple Watch's speaker.

Please note that the sound quality won't be as good as when using headphones, and the volume might be lower. Also, be aware that playing audio through the speaker can use more battery power than listening with headphones.

If your Apple Watch isn't playing sound, make sure it's not on Silent Mode. You can check this by swiping up on your watch face to open the Control Center, then look for the bell icon. If it's highlighted, your watch is on Silent Mode. Tap the bell to turn off Silent Mode.