barbule

A small bird preens a single barbule on its wing.

Definition

1. Noun:
   • A small barb or pointed projection: In biology, "barbule" refers to one of the minute, hooked or barbed filaments that branch from the barbs of a feather, interlocking to form the vane.
   • A secondary barb: In a broader sense, a "barbule" can also denote a small barb or a subdivision of a barb, especially in the structure of feathers or certain plants.

Usage Examples

• Noun:
  • Each barbule on the feather hooks onto adjacent barbules, creating a smooth, continuous surface. (The tiny filaments on the feather's barbs interlock to form the vane.)
  • Under a microscope, the barbules appear as tiny, comb-like structures. (The small barbed projections are visible only with magnification.)
  • The bird's plumage is made up of barbs and barbules that give the feather its strength and shape. (The feather is composed of branching filaments.)

Advanced Usage

• "barbule" as a technical term in ornithology: In the study of birds, the barbule is a key component of feather structure. It is often described in relation to the rachis (central shaft), barbs (main branches), and barbicels (hooks on barbules).

  • The barbules with barbicels lock together to form a waterproof vane in aquatic birds. (The hooked barbules create a sealed surface for water repellency.)

• In botany: Some plants, such as certain grasses or cacti, have structures called "barbules" that are small, backward-pointing projections used for attachment or defense.

  • The barbules on the cactus spine help it cling to animal fur for seed dispersal. (The tiny barbs aid in attachment.)

Variants and Related Words

• Barb (n): a sharp projection or point, often found on fishhooks, arrows, or feathers.

  • The barb of the hook prevents the fish from escaping. (The backward-pointing projection holds the fish.)

• Barbed (adj): having a barb or barbs; sharp and pointed.

  • The barbed wire fence is dangerous to touch. (The wire has sharp points.)

• Barbicel (n): a microscopic hook on a barbule that attaches to adjacent barbules.

  • The barbicels are essential for feather integrity. (The hooks keep the feather's vane intact.)

Synonyms

• Spicule: a small, needle-like structure (often used in biology for similar projections).
• Hooklet: a tiny hook or barb (less common, but synonymous in feather anatomy).
• Fibril: a small fiber or filament, though not necessarily barbed.

Related Idioms

• The word is primarily used in scientific contexts, such as ornithology or botany.