粘合 (nián hé) is a verb meaning 'to bond' or 'to adhere', describing the physical process where two surfaces stick together, often with glue, heat, pressure, or natural adhesion. The first character 粘 (nián) means 'sticky' or 'to stick', while the second character 合 (hé) means 'to join', 'to unite', or 'to close'. Together, they emphasize the action of causing separate things to become firmly attached as one unit.

This term is commonly used in medical contexts (e.g., tissue adhesion after surgery), manufacturing (e.g., bonding materials), and everyday repair tasks. It carries a neutral, slightly technical tone — more formal than colloquial alternatives like 粘住 (niān zhù). While it can describe natural adhesion (e.g., wound healing), it’s most frequently applied to intentional, engineered bonding processes requiring precision or durability.