a mark made by cutting or stamping: anything engraved, branded, or carved into a surface
At its root this word names the thing produced by scratching or incising something: an engraved figure, a stamped impression, a brand burned into skin, a device cut into a coin, a shape chiseled out of stone. In the ordinary speech of the first century it was a common, even bureaucratic, word. It could mean the official stamp an emperor's office pressed onto a contract to make it legal, the portrait struck on a coin, the brand that marked an animal or a slave as someone's property, the tattoo a temple put on its devotees, or simply a sculpted object.
The New Testament uses the word in two of these directions. Luke uses it once for a sculpted idol, an object shaped by human hands. John uses it eight times in Revelation for the notorious mark of the beast, worn on the right hand or forehead. The two uses are not different words but two faces of the same idea: in each case something has been deliberately stamped or carved to mark out what it is and whose it is. That shared core, a mark imposed to declare ownership or identity, is what holds the senses together.