'联合' (liánhé) is a compound word formed from two characters: '联' (lián), meaning 'to connect' or 'to link', and '合' (hé), meaning 'to join' or 'to combine'. Together, they convey the idea of bringing separate entities together for a shared purpose — whether people, organizations, countries, or ideas. As a verb, it emphasizes the action of uniting; as an adjective, it describes something that is jointly operated or co-owned.

This word is commonly used in formal, institutional, or cooperative contexts — such as international alliances, business partnerships, academic collaborations, or joint ventures. It carries a neutral-to-positive connotation and implies intentionality, coordination, and mutual agreement. You’ll often see it in news headlines, official documents, and organizational names (e.g., 联合国 — United Nations). Unlike casual terms like '一起' (yìqǐ), '联合' suggests structured, purpose-driven cooperation rather than simple simultaneity.