sessile (2009-05-05)

Part of Speech: adjective

Pronunciation: ['se-sêl or 'se-sIL]

Definition: (1) Attached directly to a base, as a leaf or flower might be attached directly to a stalk without a stem (pedicle). (2) Firmly attached and immobile.

Usage: The difference between this word and "sedentary" is that while "sedentary" implies an attachment to sitting, "sessile" suggests an attachment to what one is sitting on: "Oblomov lived a sedentary youth and in his old age became positively sessile." Thus today's word is not a synonym of "sedentary," but an emphatic alternative, "Brigit has become such a sessile fixture of her recliner chair, I fear she has grown to it." W. H. Auden once spoke of a "sessile hush," a hush that refused surrender its place to the urgence of time.

Suggested Usage: Today's word is used mostly in scientific terminology, referring to flowers like the trillium, fruit like the jack-fruit that grow directly from a stalk, or the eyes of most animals as opposed to those of crabs that are on a stalk. In the second sense, scallops are the opposite of the sessile barnacle; they are vagile, which is to say, mobile. As usual, that doesn't mean we cannot find nonscientific uses.

Etymology: The word for "sit" in all Indo-European languages comes from the same source, Proto-Indo-European *sed-: Spanish sentar(se), French (s')asseoir, Russian sadit'(sya), German "sitzen" and English "sit," "set," "seat." The verb in Latin was "sedere," the past participle of which is "sessus." Latin sessilis "sitting down, stunted," whence today's word, was based on the participle. You might think that "chair" would be related to this root—and you would be right. The [s] became an [h] in Greek (remember Latin "semi-" = Greek "hemi-"?) so, with the suffix –ra, "hedra" became "seat" in Greek. Prefixed with kat(a) "down," the direction most folks sit in, it became "cathedra," a word borrowed by Latin in the sense of "armchair, cushioned chair." (The cathedral church is the one with the bishop's cathedra or throne.) Old French hammered this word into "chaière" and we polished it down to "chair."