In heraldry, drops are usually understood through the classic charge called the goutte, a stylized droplet whose meaning depends heavily on context and tincture. At the most general level, drops suggest essence, outpouring, sacrifice, purification, and life-giving fluid. Because a drop is small yet potent, it can represent something concentrated and significant, whether that is blood shed in battle, water sustaining a community, oil used in blessing, or tears expressing grief and compassion. This gives the symbol an unusual richness, since it can speak either of hardship endured or of grace received.
Heraldic tradition is especially precise with drops because different colors are often read as different substances. A red drop may be blazoned as gouttes de sang, meaning drops of blood, and naturally points toward courage, martyrdom, or wounds honorably borne. Blue or white drops can suggest water, dew, or purity, while gold drops may imply wealth, divine favor, or precious abundance. Black drops have been associated with pitch or oil, and other forms such as gouttes de larmes connect the symbol with tears and sorrow. In practice, drops may appear singly, in ordered groups, or scattered across a field, and they are especially effective when the arms wish to stress a connection to rivers, healing, consecration, endurance, or remembered suffering.
As a heraldic device, drops are less about rank than about meaningful substance. They often appear in civic, religious, and personal arms where the liquid itself carries symbolic weight. Their simplicity also makes them visually strong, particularly when repeated in a patterned field. For general heraldic background on how such symbols function as charges, Wikipedia: Charge (heraldry) is a useful starting point. Taken as a whole, drops in heraldry convey concentrated meaning: life, sacrifice, cleansing, memory, and blessing made visible in a small but eloquent form.