from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A hair or hairlike structure, especially on the surface of a cell or microorganism.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A hair.
  • n. A hairlike appendage found on the cell surface of many bacteria.

from The Century Dictionary and Cyclopedia

  • n. In botany, one of the fine slender bodies, like hair, covering some plants.
  • n. In zoology, a hair or hair-like body, especially a hair in any way distinguished from those which collectively cover the body.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. hairlike structure especially on the surface of a cell or microorganism
  • n. any of the cylindrical filaments characteristically growing from the epidermis of a mammal


(American Heritage® Dictionary of the English Language, Fourth Edition)
From the Latin hair (Wiktionary)


  • It does explore the topic of homology between the flagellar axial proteins rod-hook-filament and the T3SS pilus, which is incredibly useful.

    When did ID "Jump the Shark"? - The Panda's Thumb

  • The pilus is a long, hair-like appendage that the bacterium uses to reach out to human cells that it infects.


  • A bacterium connects itself to another through a tube structure called pilus (there are lots of them, spiky things, plural: pilli), you can see them in the second illustration in this article (scroll up).

    Medlogs - Recent stories

  • Stultissimus pilus occipitis mei plus scit, quam omnes vestri doctores, et calceorum meorum annuli doctiores sunt quam vester Galenus et Avicenna, barba mea plus experta est quam vestrae omnes Academiae.

    Anatomy of Melancholy

  • “Ubera tua intumuerunt, et pilus tuus germinavit; et eras nuda et confusione plena.” — “Thy breasts were fashioned, and thy hair was grown, and thou wast naked and confused.”

    A Philosophical Dictionary

  • The pilus prior commanded a cohort; the primipilus a legion.

    Antony and Cleopatra

  • Antony called a war council, not a meeting of his intimates but a gathering that included all his legates and tribunes, plus the primipilus and pilus prior centurions—sixty men altogether.

    Antony and Cleopatra

  • A desperate pilus stretched from the outer flank of Ekarete's ship.

    The Year's Best Science Fiction 23rd Annual Collection

  • A pilus extended from Tasmin's ship; Yalnis's ship accepted it.

    The Year's Best Science Fiction 23rd Annual Collection

  • Air rushed past Yalnis in a quick blast; the wind fell still as her ship clenched its pilus and resorbed it.

    The Year's Best Science Fiction 23rd Annual Collection


Log in or sign up to get involved in the conversation. It's quick and easy.

  • "There are two key components to the bacteria's assault on a human body: the TCP pilus that allows it to replicate with such exponential fury in the small intestine, and the cholera toxin that actually triggers the rapid dehydration of the host. Mekalanos and Waldor discovered that the gene for cholera toxin is actually supplied by an outside source: a virus called CTX phage.... As unlikely as it sounds, V. cholerae is not a born killer. It needs the CTX phage to switch over to the dark side."
    —Steven Johnson, The Ghost Map (New York: Penguin, 2006), 246

    October 4, 2008