Definition of sessile in US English:

sessile

adjective

Biology
  • 1(of an organism, e.g. a barnacle) fixed in one place; immobile.

    • ‘It is also suggested that the reef may be a source of pelagic larvae of sessile organisms that may settle on mangrove roots for greater diversity.’
    • ‘Most radially symmetric animals are sessile, however, echinoderms are able to move.’
    • ‘Epizoic barnacles are sessile, marine crustaceans and constitute a model system featuring the above conditions.’
    • ‘Alternatively, competent larvae of many sessile invertebrate species do not progress toward metamorphosis if stimulatory cues are absent.’
    • ‘Because anemones are sessile animals, staying put most of their lives, it is important for them to maintain dominance over their territory in competition for food and space.’
    1. 1.1Zoology Botany (of a plant or animal structure) attached directly by its base without a stalk or peduncle.
      ‘sporangia may be stalked or sessile’
      • ‘It frequently occurs in the lower uterine segment and may be either sessile or pedunculated.’
      • ‘These two phenomena are especially critical for sessile higher plants.’
      • ‘It continues to grow with a dome shape, but it can be sessile or pedunculated.’
      • ‘The genus is about equally divided into two subgenera, those with pedicellate flowers (Trillium L.) and those with sessile flowers (Phyllantherum Raf.).’
      • ‘The tumors were described as pedunculated or sessile polypoid nodules or as cauliflower-like masses projecting into the lumen of the gallbladder.’

Origin

Early 18th century: from Latin sessilis, from sess- ‘seated’, from the verb sedere.

Pronunciation