1. any of various weedy plants, especially those of the amaranth family, that are considered undesirable in gardens and crops

Examples

• The farmer spent hours pulling pigweed from his cornfield.
• Pigweed can quickly take over a vegetable garden if left unchecked.
• Some species of pigweed are actually edible and nutritious.
• The herbicide was specifically designed to target pigweed and other common weeds.
• Pigweed seeds can remain viable in the soil for many years.
• Despite being called a weed, pigweed has been used as food in some cultures.