Duck/dʌk/ Definition 1 of 5Pro Tip 1/2Water Habitats Ducks are associated with water; use this term for birds commonly seen around ponds and lakes. Children love feeding the ducks at the lake. Pro Tip 2/2Not Just Any Bird Use 'duck' to refer specifically to these water birds, not all birds in general. A sparrow is not a duck; it's much smaller and doesn't swim.