1. a fish that can inflate its body with water or air when threatened, especially a pufferfish

Examples

• The swellfish quickly inflated when the diver approached.
• Many swellfish species are found in tropical waters.
• The aquarium’s swellfish exhibit was popular with children.
• Swellfish use their ability to puff up as a defense mechanism.
• The chef warned that some swellfish contain dangerous toxins.
• We spotted a small swellfish hiding among the coral.