fossil

1. (paleontology) Any preserved evidence of ancient life, including shells, imprints, burrows, coprolites, and organically-produced chemicals.Examples: "He draws eclectically on studies of baboons, descriptive anthropological accounts of hunter-gatherer societies and, in a few cases, the fossil record."; "You know what, we’ve got a limited number of heartbeats in this world so if you’re only truly happy researching fossils and can make it work for you, you go for it."

2. (linguistics) A fossil word.

3. (figuratively) Anything extremely old, extinct, or outdated.figuratively

4. (figuratively, derogatory) An extremely old or outdated person.Examples: "I do not want to convey any disrespectful notion or slight when I call those good and learned men fossils, but my experience is that people are apt to fossilise even at a University if they follow the same paths too persistently."; "All at once there was a tapping at the window pane. Atherton was staring at us from without. He shouted through the glass, ‘Come out of that, you fossils! — I’ve news for you!’"derogatoryfiguratively