‘结姻’ literally means ‘to tie (结) a marital (姻) bond’ and refers to the formal establishment of a marriage alliance—typically between two families, clans, or even animal lineages in classical or literary contexts. While it can describe human marriages in historical or ceremonial settings, it is especially common in classical Chinese literature and zoological or agricultural discourse when describing intentional breeding partnerships between animals (e.g., pairing elite livestock for selective breeding).

The term carries a sense of formality, intentionality, and social or strategic purpose—not just romantic union but a deliberate alliance with shared goals like improving bloodlines, consolidating resources, or strengthening kinship ties. It’s more elevated and less colloquial than ‘结婚’ (to get married) and often appears in written or ritual language rather than everyday speech.