The word "with" is a preposition that indicates a relationship between things. It is used to express the idea of being alongside, together, or in the company of someone or something. For example, if you say "I am going with my friend," it means that you will be accompanying your friend.
The word "with" originates from the Old English "wiĆ°," which means "against" or "in opposition." Over time, its meaning evolved to indicate companionship or support.