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Synonyms

guano

American  
[gwah-noh] / ˈgwɑ noʊ /

noun

  • guanos
    plural
  1. a natural manure composed chiefly of the excrement of sea birds, found especially on islands near the Peruvian coast.

  2. any similar substance, as an artificial fertilizer made from fish.


guano British  
/ ˈɡwɑːnəʊ /

noun

    1. the dried excrement of fish-eating sea birds, deposited in rocky coastal regions of South America: contains the urates, oxalates, and phosphates of ammonium and calcium; used as a fertilizer

    2. the accumulated droppings of bats and seals

  1. any similar but artificial substance used as a fertilizer

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

guano Scientific  
/ gwänō /
  1. A substance composed chiefly of the dung of sea birds or bats, accumulated along certain coastal areas or in caves and used as fertilizer.

  2. Any of various similar substances, such as a fertilizer prepared from ground fish parts.


Other Word Forms

Noun Inflected Forms

Etymology

Origin of guano

First recorded in 1595–1605; from Spanish: “fertilizer, dung”; Latin American Spanish huano “dung,” from Quechua wanu “dung for fuel, fertilizer”

Explanation

Guano is bird or bat poop. If you park your car near the harbor, your windshield may end up covered in seagull guano. Ew. You'll most often find the word guano used for the specific bird (or bat) manure that's used as a fertilizer in gardens. In fact, the term is so common that some fertilizers are called guano even when they don't contain actual bird poop. Guano, a Spanish word with Quechua roots, is rich in nitrogen, potassium, and other nutrients that help plants grow.

Keep Reading on Vocabulary.com

Vocabulary lists containing guano

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Their collective body heat raises the cave’s temperature to a sweltering 106°F, and the piles of guano beneath them are deep enough to bury the Statue of Liberty to her waist.

From The Wall Street Journal Jun. 19, 2026

"Together, the chemical and material evidence we studied confirms earlier scholarship showing that guano was deliberately collected and used as a fertilizer," Dr. Bongers said.

From Science Daily Mar. 7, 2026

The latter elements suggest the hearth was intentionally sealed with a mixture of guano and sand, which can protect plant materials within the hearth from catching fire—conditions needed to create tar.

From Science Magazine Nov. 22, 2024

Their guano, or dung, can also be used as fertilizer.

From Los Angeles Times Oct. 31, 2024

“Did somebody step in that bat guano in the other room?”

From "The Smartest Kid in the Universe" by Chris Grabenstein

It has been estimated that Texas guanos alone consume 6,600 tons of insects each year.

From Time Magazine Archive

Such guanos form a soft phosphatic rock, and are extremely rich in phosphates.

From Manures and the principles of manuring by Charles Morton Aikman

There is no doubt, however, that such guanos are very useful, and if obtained in large quantity, and of uniform composition, would be used to a much larger extent than they at present are.

From Elements of Agricultural Chemistry by Thomas Anderson

The following is a list of the more common nitrogenous and phosphatic guanos which have been used in the past or are at present in use.

From Manures and the principles of manuring by Charles Morton Aikman

As examples of these "crust" guanos may be mentioned Sombrero, Curaçao, Aruba, Mexico, and Navassa phosphates.

From Manures and the principles of manuring by Charles Morton Aikman

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