A dagger is a knife with a very sharp point designed or capable of being used as a thrusting or stabbing weapon. Daggers have been used throughout human experience for close combat confrontations, and many cultures have used adorned daggers in ritual and ceremonial contexts. The distinctive shape and historic usage of the dagger have made it iconic and symbolic. A dagger in the modern sense is a weapon designed for close-proximity combat or self-defence; due to its use in historic weapon assemblages, it has associations with maleness and martiality. Double-edged knives, however, play different sorts of roles in different social contexts. In some cultures, they are neither a weapon nor a tool; but a potent symbol of manhood; in others they are ritual objects used in sacred body modifications such as circumcision.
A wide variety of thrusting knives have been described as daggers, including knives that feature only a single cutting edge, such as the European rondel dagger or the Persian pesh-kabz, or, in some instances, no cutting edge at all, such as the stiletto of the Renaissance. However, in the last hundred years or so, in most contexts, a dagger has certain definable characteristics, including: a short blade with a sharply tapered point, a central spine or fuller, and usually two cutting edges sharpened the full length of the blade, or nearly so. Most daggers also feature a full crossguard to keep the hand from riding forwards onto the sharpened blade edges.
Daggers are primarily weapons, so knife legislation in many places restricts their manufacture, sale, possession, transport, or use.
The earliest daggers were made of materials such as flint, ivory or bone in Neolithic times.
Copper daggers appeared first in the early Bronze Age, in the 3rd millennium BCE, and copper daggers of Early Minoan III (2400–2000 BCE) were recovered at Knossos.