Zoology. permanently attached; not freely moving.
Botany. attached by the base, or without any distinct projecting support, as a leaf issuing directly from the stem.
And I was afraid of being grounded, sessile —stuck in one spot for eighteen years of oboe lessons and math homework that I couldn’t finish the first time around.
— Ariel Levy , “Thanksgiving in Mongolia,” The New Yorker , Nov. 18, 2013
Alfred was stretched out his full length in the sword of sun that shone through the thick branches of the sessile oak trees.
— Catherine Coulter , Rosehaven , 1997
Sessile stems from the Latin word sessilis which had a range of meanings including “fit for sitting on, low enough to sit on, and dwarfish (when referring to plants).” It entered English in the early 1700s.