companion

A friend, acquaintance, or partner; someone with whom one spends time or keeps company

"His dog has been his trusted companion for the last five years."

A person employed to accompany or travel with another.

The framework on the quarterdeck of a sailing ship through which daylight entered the cabins below.

The covering of a hatchway on an upper deck which leads to the companionway; the stairs themselves.

To be a companion to; to attend on; to accompany.

To qualify as a companion; to make equal.