1. Plural of hammerhead; large sharks with a flattened, hammer-shaped head.
Usage: Most common sense; refers to the family Sphyrnidae
2. Plural of hammerhead; a tool with a head shaped like a hammer, used for driving nails or breaking things.
Usage: Less common; refers to the tool itself rather than the shark
3. Plural of hammerhead; a person who is stubborn or thick-headed.
Usage: informal; derogatory

Examples

• The aquarium's newest exhibit features several hammerheads swimming in the large tank.
• Hammerheads are known for their distinctive head shape, which helps them detect prey.
• The carpenter kept several hammerheads of different sizes in his toolbox.
• Don't be such a hammerhead—just listen to what I'm trying to tell you.
• Scientists study hammerheads to understand how their unusual anatomy aids hunting.
• The divers spotted a school of hammerheads near the reef.