Definition of peristome in English:

peristome

noun

Zoology
  • 1The parts surrounding the mouth of various invertebrates.

    • ‘Ammonites are complete, many with preserved peristomes.’
    • ‘The autozooids have small apertures and often preserve long peristomes inclined at an acute angle to the colony surface.’
    • ‘Other mature modifications, such as change in the shape of the peristome, are also inconsistently observed in Paleozoic ammonoids.’
    • ‘The peristome can seem quite large.’
    • ‘Spines and tube feet surrounding the peristome function in locomotion, burrowing, and food-gathering.’
    1. 1.1Botany A fringe of small projections around the mouth of a capsule in mosses and certain fungi.
      • ‘The sporophytes also develop peristomes and a spongy layer.’

Origin

Late 18th century: from modern Latin peristoma, from Greek peri- around + stoma mouth.

Pronunciation:

peristome

/ˈperəˌstōm/