fossil

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A remnant or trace of an organism of a past geologic age, such as a skeleton or leaf imprint, embedded and preserved in the earth's crust.
2. n. One, such as a rigid theory, that is outdated or antiquated.
3. n. Linguistics A word or morpheme that is used only in certain restricted contexts, as kempt in unkempt, but is otherwise obsolete.
4. n. Linguistics An archaic syntactic rule or pattern used only in idioms, as so be it.
5. adj. Characteristic of or having the nature of a fossil.
6. adj. Being or similar to a fossil.
7. adj. Belonging to the past; antiquated.

Century Dictionary and Cyclopedia

1. Dug out of the earth: as, fossil coal; fossil salt.
2. Pertaining to or resembling fossils; preserved by natural inhumation, as an organic body, in form and sometimes in texture: as, fossil shells, bones, or wood. See II., 2.
3. Figuratively, antiquated; superannuated; outgrown; belonging to a past epoch or discarded system: as, a fossil statesman; fossil manners or literature.
4. n. Any rock or mineral, or any mineral substance, whether of an organic or of an inorganic nature, dug out of the ground.
5. n. Specifically, in later geological and mineralogical use, anything which has been buried beneath the surface of the earth by natural causes or geological agencies, and which bears in its form or chemical composition the evidence that it is of organic origin. Thus, the shell of a mollusk may be preserved unchanged, in both form and chemical composition; or, while retaining its original form, it may have been converted into silica; or it may have disappeared entirely, leaving only a cast as evidence of its former existence; or there may remain only a mold of its interior, formed after the soft parts had entirely decayed: in any of these cases, the specimen or fragment of rock which thus shows by its form that it, either wholly or in part, belonged to an organic body, or that its configuration resulted from the presence of something having had an organized existence, would be properly called a fossil. Even the rocks showing traces of trails, footprints, bored cavities, or other evidences of contact with organic life, are usually designated as fossils. The bones or other remains of species now living on the earth, if buried by any recent catastrophe, such as a flood or landslide, would not, as a general rule, be designated as fossil, but would be called recent. If, however, such an entombment took in prehistoric times, the term fossil would by most geologists be used in describing the occurrence in preference to recent.
6. n. Hence, figuratively, one who or something which is antiquated, or has fallen behind the progress of ideas; a person or thing of superannuated or discarded character or quality: as, a curious literary fossil.

Wiktionary

1. n. The mineralized remains of an animal or plant.
2. n. paleontology Any preserved evidence of ancient life, including shells, imprints, burrows, coprolites, and organically-produced chemicals.
3. n. linguistics A fossilized term.
4. n. figuratively Anything extremely old, extinct, or outdated.

GNU Webster's 1913

1. adj. Dug out of the earth
2. adj. preserved from a previous geological age; from deep wells; -- usually implying that the object so described has had its substance modified by long residence in the ground, but also used (as with fossil water) in cases where chemical composition is not altered.
3. adj. (Paleon.) Like or pertaining to fossils; contained in rocks, whether petrified or not.
4. n. obsolete A substance dug from the earth.
5. n. (Paleon.) The remains of an animal or plant found in stratified rocks. Most fossils belong to extinct species, but many of the later ones belong to species still living.
6. n. colloq. A person whose views and opinions are extremely antiquated; one whose sympathies are with a former time rather than with the present.

WordNet 3.0

1. n. the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil
2. n. someone whose style is out of fashion
3. adj. characteristic of a fossil