companion (n)

I always walk to school with my companion Frank.
The loyal dog became a faithful companion to the elderly woman, bringing joy and comfort to her daily life.
As a travel companion, she explored new cities with a sense of adventure and shared experiences with like-minded friends.
The novel's protagonist found an unexpected companion in the mysterious stranger who appeared during a crucial moment in the story.
In the vastness of space, an astronaut's only companion is the onboard artificial intelligence that assists with daily tasks and mission operations.