What's the "een" in Halloween?
1610s, "any thing dug up;" 1650s (adj.) "obtained by digging," from French fossile (16c.), from Latin fossilis "dug up," from fossus, past participle of fodere "to dig," from PIE root *bhedh- "to dig, pierce."
Restricted noun sense of "geological remains of a plant or animal" is from 1736; slang meaning "old person" first recorded 1859. Fossil fuel (1835) preserves the earlier, broader sense.
The remains or imprint of an organism from a previous geologic time. A fossil can consist of the preserved tissues of an organism, as when encased in amber, ice, or pitch, or more commonly of the hardened relic of such tissues, as when organic matter is replaced by dissolved minerals. Hardened fossils are often found in layers of sedimentary rock and along the beds of rivers that flow through them. See also index fossil, microfossil, trace fossil.
The evidence in rock of the presence of a plant or an animal from an earlier geological period. Fossils are formed when minerals in groundwater replace materials in bones and tissue, creating a replica in stone of the original organism or of their tracks. The study of fossils is the domain of paleontology. The oldest fossils (of bacteria) are 3.8 billion years old.
Note: The term is used figuratively to refer to a person with very old-fashioned or outmoded viewpoints: “That old fossil thinks that men should wear suits at the theater!”
1. In software, a misfeature that becomes understandable only in historical context, as a remnant of times past retained so as not to break compatibility. Example: the retention of octal as default base for string escapes in C, in spite of the better match of hexadecimal to ASCII and modern byte-addressable architectures. See dusty deck.
2. More restrictively, a feature with past but no present utility. Example: the force-all-caps (LCASE) bits in the V7 and BSD Unix tty driver, designed for use with monocase terminals. (In a perversion of the usual backward-compatibility goal, this functionality has actually been expanded and renamed in some later USG Unix releases as the IUCLC and OLCUC bits.)
3. The FOSSIL (Fido/Opus/Seadog Standard Interface Level) driver specification for serial-port access to replace the brain-dead routines in the IBM PC ROMs. Fossils are used by most MS-DOS BBS software in preference to the "supported" ROM routines, which do not support interrupt-driven operation or setting speeds above 9600; the use of a semistandard FOSSIL library is preferable to the bare metal serial port programming otherwise required. Since the FOSSIL specification allows additional functionality to be hooked in, drivers that use the hook but do not provide serial-port access themselves are named with a modifier, as in "video fossil".