粘连 (nián lián) is a verb meaning 'to stick together' or 'to adhere', often describing an abnormal physical bonding between tissues, surfaces, or objects that should remain separate. The first character 粘 (nián) means 'sticky' or 'to stick', while the second 连 (lián) means 'to connect' or 'to join' — together they emphasize a persistent, often unwanted adhesion. This term is especially common in medical contexts, such as describing scar tissue forming between internal organs after surgery or inflammation.

Outside medicine, 粘连 can also describe everyday situations where substances cling stubbornly — like wet paper pages sticking together or melted plastic adhering to a pan. However, it carries a slightly technical or clinical nuance and is rarely used for simple, temporary sticking (e.g., tape on paper). It implies resistance to separation and often suggests an undesirable or pathological condition requiring intervention.