The word "tend" generally means to have a tendency to do something, to take care of something, or to attend to it in some way. It implies a regular or habitual action or feeling toward someone or something. For example, if you "tend to your garden," you're regularly taking care of the plants, or if you "tend to be late," you often arrive late.
The word "tend" originates from the Latin word "tendere," which means "to stretch" or "to aim for." This evolved into the Old French word "tendre" and eventually into Middle English as "tenden," leading to the modern form we use today.