In heraldry, the dagger is a weapon charge that usually signifies readiness for combat, courage in close action, justice, sacrifice, and personal honor defended at intimate risk. Unlike the sword, which often carries broader associations with knighthood, authority, and formal military command, the dagger suggests swiftness, vigilance, and resolve in moments of immediate danger. It can mark a family tradition of military service, a reputation for bold defense, or a willingness to protect sovereign, household, or faith under pressure. Because it is compact and direct, the dagger may also imply decisiveness and disciplined force rather than pageantry. In some armorial contexts it can point to martyrdom or violent death, especially when paired with religious imagery or used in memorial arms, though its meaning depends heavily on the overall composition. As a heraldic symbol, the dagger speaks most strongly of courage at close quarters, protective strength, and honor maintained through action rather than display.

Daggers appear in a range of European heraldic traditions, especially in Scottish armory, where the dirk and similar blades are closely connected with clan identity and martial heritage. A well-known related example is the use of the Scottish dirk in clan badges and crests, where the weapon reinforces ideas of loyalty, defense, and ancestral warrior culture. In broader heraldic design, a dagger may be shown upright, downward, sheathed, or in combination with other charges, and each arrangement can affect the tone of the arms, making the symbol either aggressive, defensive, ceremonial, or commemorative. It is also sometimes used as a canting or allusive device when the family name, local history, or office has some connection to arms or military duty. In practical heraldic reading, the dagger most often represents valor, vigilance, sacrifice, martial readiness, and the determined defense of rightful cause, especially when the bearer wishes to project firmness, courage, and personal resolve.