sessile
Meaning
permanently attached to a base and not free-moving, as in the case of barnacles or corals.
attached directly by the base without a stalk or peduncle, as in the case of a leaf or flower.
Structure
Usage
barnacles are sessile creatures that spend their adult lives cemented to rocks or ship hulls.
the plant had sessile leaves growing directly from the stem without a petiole.
unlike mobile animals, sessile organisms must feed on whatever nutrients come within reach.
Etymology
the word sessile originates from the latin 'sessilis', meaning 'pertaining to sitting'. this derives from the verb 'sedēre', meaning 'to sit', a root with a deep proto-indo-european ancestry in sed-, also meaning 'to sit'. the literal sense of being seated or settled evolved into the biological terminology to describe organisms or structures that are fixed in one place, as if sitting on a surface. the suffix -ile forms an adjective, conveying the property of being permanently attached or seated, thus creating a precise term for immobility in natural science.
Analysis
sess is from latin 'sessus', the past participle of 'sedēre' meaning 'to sit'. ile is a latin adjectival suffix meaning 'pertaining to' or 'capable of'.