Other forms: fossils
A fossil is the shape of something that once lived, kept in stone. An ammonite curled into a cliff face, a fern pressed flat in slate, a dinosaur footprint that hardened where it was made.
It is not only bones. A shell, a leaf, a tooth, a footprint, even a burrow — anything the rock managed to record counts, and the creature itself is long gone: what you hold is stone in its shape. Fossil works as an adjective in fossil fuel, and the name is literal, because coal, oil and gas formed from things that lived and died. Fossilised means turned into a fossil, and both words get aimed at people and habits that stopped changing, so calling someone an old fossil is a mild insult about being stuck in the past. Everything found in the ground together makes the fossil record, which is what geologists argue over.
1nountraceThe remains or the trace of a plant or animal from long ago, preserved in rock.
“The cliff is full of fossils, most of them shells.”
2adjectiveformedFormed underground from the remains of living things long dead — said of coal, oil and gas.
“The country still gets most of its power from fossil fuels.”
3nounfossilA person or an idea hopelessly stuck in the past.
“The committee is run by fossils who still send things by fax.”
fossil is a trace of ancient life.
Fossil reached English through French fossile from Latin fossilis, which meant nothing more specific than 'something dug up', from fodio, to dig. For a long stretch it covered any object pulled out of the ground, minerals included. The narrowing to the stone shapes of dead creatures came later.
Latin
fossilis — something which has been dug up
French
fossile
English, today
fossil
Built from
From French fossile, from Latin fossilis (“something which has been dug up”), from fodio (“to dig up”).
Etymology from Wiktionary, CC BY-SA