Pandiculation

If you've ever awoken in the morning, yawned, and stretched your arms, you've experienced pandiculation. Use the noun pandiculation to describe the super relaxed combination of yawning and stretching, followed by complete relaxation.

It is nature’s way of stretching; animals are prone to pandiculation too, extending their paws in a stretch and yawning widely.

The Latin root is pandiculari, "to stretch oneself," from pandere, "to stretch."