noun
guano
GWAH-noh/ˈɡwɑːnəʊ/
Accumulated seabird or bat droppings used as fertilizer.
The gardener uses accumulated guano to fertilize the seedlings.

Etymology
Quechua huanu means “dung.” The English sense specializes that broad meaning to accumulated seabird or bat droppings used as fertilizer.
In context
… two miners are searching for bat guano, a key ingredient in making fertilizer.
More examples
- The old trade relied on guano as fertilizer.
- Bat guano covers the floor near the cave entrance.
- Workers once collected guano from these islands.
Forms
guano