system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some words in English have two or more very different meanings?

Some examples:

Run - running, blocked nose.
Wave - moving your hand, water ripple like movements.
Cool - Justin Bieber, cold.
Duck - A creature, bend down.
Ring - A circle, a onomatopoeia .
Tear - Water droplets that leak from your eyes, ripping apart things.
Bat - A flying nope mammal, a wooden stick.
Bass - Instrument, fish.
Yard - A unit of retard measurement, a garden in your house.
Dove - A bird, diving in.

The list goes on and on.
gpt
Sometimes it's the same word that evolved into having two or more different (but related) meanings. For example a "wave" is a repeated fluctuations, just like when you wave your hand (you move it side to side) or ocean waves (the water moves back and forth). Sometimes the two meanings are far enough from each other so that it doesn't seem like they have the same origin, but they do - for example "duck" means "to plunge into" something, which is why the bird is called duck - because it plunges into the water.

Sometimes they're two entirely different words, usually from different languages, which evolved into being written the same or even sounding the same. These are known as homographs or homophones. For example the fish "bass" comes from Middle English *baers* while the musical instrument "bass", which comes from the word for a low note, comes from the latin *bassus* which means low (similar to the English word "base").