To cause pain or damage to a person or living creature. It can also be used to express mental pain or anguish as well as physical pain.
For example: This injection won't hurt.
She hurt my feelings with what she said.
The bright sun hurts may eyes.
When this verb is used intransitively (without a direct object) it always means pain, however when it is used transitively (with a direct object) it refers to pain and or damage.
For example: Ouch! That hurts.
You have hurt the muscles in your leg, the ligaments are damaged.
Generally (but not exclusively) hurt refers to pain, harm or damage to a living creature. Me, a person, a dog, a tree a plant. We usually use the verb to damage for non living things. So we say you damaged my bike, not hurt. Let us contrast: The decoration and colour scheme hurt his eye. (it is ugly). The decoration and colour scheme damaged his eye. (he needs to go to hospital).
We can use hurt when we are talking about a negative impact on sales figures, profits, schedules or statistics. Here we can consider the hurt as a cut or a wound to the numbers.
For example: The recent rain has severely hurt our sales figures.
The loss of his job hurt his family's income.
Hurt can be an adjective.
For example: He couldn't walk well, because of his hurt leg.
Hurt can be used as a noun that is almost always uncountable.
For example: It took many years to get over (recover from) the hurt of the war years.
Hurtful is an adjective meaning painful.
For example: The way she ignored me was hurtful.