An abbreviation of idem.A common termination in adjectives (and nouns derived from adjectives) of Latin origin, as in acid, arid, fluid, vivid, turbid, morbid, flaccid, frigid, torrid, solid, etc. It is not used as a formative in English.[NL. -idum, neut. of L. -idus.] In chem., a formative (also spelled -ide, and when so spelled generally pronounced -īd) suffixed to names of elements to form names of compounds, as in oxid, chlorid, bromide, iodide, sulphid, etc., designating compounds of oxygen, chlorin, bromine, iodine, sulphur, etc.The termination of nouns Englished from Latin or New Latin feminine nouns (ultimately Greek or on the Greek model) in -is, as caryatid, hydatid, etc.In zoology, the termination of nouns Englished from Latin or New Latiu nouns in -idæ, as felid, from Felidæ, fringillid, from Fringillidæ, etc.n. In Weismann's doctrine of germ-plasm, the substance of inheritance or the bearer , in the germ-plasm, of the hereditary qualities of a single complete organism, orn. in the somatic idioplasm of the hereditary qualities of a group of cells or a part of a developing embryo or growing organism.n. n. This termination affords a simple and regular method of transforming a family name ending in -idæ into a common ‘English’ noun serving as a name for any member of the family. Thus, any member of the Felidæ is a felid, any of the Bradypodidæ a bradypodid, any of the Gadidæ a gadid, etc. This overcomes the ambiguity of using the popular name of some member of the family as a common name for all. The popular name is often not conterminous in meaning with the New Latin name and it always has a set of cross associations that are absent from the New Latin name. The two kinds of names do not cover the same ground. Every member of the Bradypodidæ is a sloth, but not every member of the Gadidæ is a cod, as several other well-known fishes, such as the pollack and haddock, are members of that family.n. A termination used by Osborn to designate the cusps of the lower teeth: for example, the cusp on a lower molar that corresponds to the hypocone of an upper tooth is the hypoconid, etc.
