1. the dried excrement of seabirds or bats, used as fertilizer

Examples

• The island was covered in thick layers of guano from centuries of seabird nesting.
• Farmers prize guano as an excellent natural fertilizer for crops.
• The cave floor was deep with bat guano that had accumulated over many years.
• Workers carefully harvested the guano from the rocky cliffs.
• Guano deposits were once so valuable they caused international disputes.
• The organic garden thrived after being treated with guano fertilizer.