To overpack means to put too many things in a suitcase, bag, or container, usually more than you actually need. When someone overpacks for a week at summer camp, they might stuff three extra pairs of shoes, seven sweaters, and a dozen books into their duffel bag, making it so heavy they can barely lift it.

Overpacking often happens when people worry they might need something and pack “just in case.” A student might overpack their backpack with every single notebook and textbook even though they only need materials for three classes that day. The result? A painfully heavy bag and a sore back.

Experienced travelers have learned that overpacking creates problems: heavy bags are harder to carry, airlines charge fees for overweight luggage, and you waste time digging through mountains of stuff to find what you actually need. That's why many people try to pack light, bringing only what they'll truly use. The opposite of overpacking is underpacking, which means bringing too little, though most people would rather have slightly too much than find themselves without something they need.