- a natural manure composed chiefly of the excrement of sea birds, found especially on islands near the Peruvian coast.
- any similar substance, as an artificial fertilizer made from fish.
- 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
- the accumulated droppings of bats and seals
- any similar but artificial substance used as a fertilizer
