Definition

1. Noun:
   • The externally visible cartilaginous structure of the external ear: In anatomy, the "pinna" is the outer, visible part of the ear that projects from the head, composed of cartilage and skin, which collects sound waves.
   • A division of a usually pinnately divided leaf: In botany, a "pinna" is a primary leaflet or segment of a compound leaf, especially one that is arranged like a feather along a central axis.

Usage Examples

• Anatomical Sense:
  • The shape of the human pinna helps to funnel sound into the ear canal.
  • Some animals can move their pinnae to better locate the source of a sound.
• Botanical Sense:
  • The fern's frond is divided into numerous small pinnae.
  • Each pinna of the compound leaf has its own tiny veins.

Advanced Usage

• "Pinnae" (plural form): Used when referring to more than one anatomical structure or leaf division.
  • The biologist studied the pinnae of various mammalian species.
  • The leaf's pinnae were arranged symmetrically along the rachis.

Variants and Related Words

• Auricle (n): A synonym for the anatomical "pinna," especially in human anatomy.
  • The auricle is another term for the visible part of the outer ear.
• Pinnate (adj): Describing a compound leaf with leaflets arranged on each side of a common axis, like a feather.
  • The tree has attractive pinnate leaves.
• Pinnule (n): A secondary division of a pinna, especially in ferns.
  • The fern's pinnae were further subdivided into delicate pinnules.

Synonyms

• For the ear: Auricle, outer ear.
• For the leaf: Leaflet, segment (in the context of a compound leaf).

Related Terms (Not Phrasal Verbs)

• Tragus (n): A small pointed eminence of the external ear, situated in front of the concha.
  • The tragus is a part of the pinna.
• Antitragus (n): A small tubercle on the pinna of the ear, opposite the tragus.
  • The antitragus is located on the lower part of the pinna.
• Rachis (n): The main axis or stem of a compound leaf or frond, to which the pinnae are attached.
  • The pinnae are attached to the central rachis.

Noun

1. the externally visible cartilaginous structure of the external ear
2. division of a usually pinnately divided leaf