绳索 (shéng suǒ) is a compound noun meaning 'rope' or 'cord' — a strong, flexible length of twisted or braided material used for pulling, tying, securing, or climbing. The first character, 绳 (shéng), originally referred to a twisted fiber cord and carries the core meaning of 'rope'; the second, 索 (suǒ), means 'rope', 'cable', or 'to search', but in this compound it reinforces the idea of a strong, functional line — not 'searching'. Together, they form a slightly formal or literary synonym for 绳 (shéng) alone, often implying durability and purpose, especially in outdoor, industrial, or safety-related contexts.

You’ll commonly encounter 绳索 in descriptions involving animals (e.g., tethering livestock), mountaineering, sailing, rescue operations, or traditional crafts. Unlike the more general and colloquial 绳, 绳索 tends to appear in written language, manuals, instructions, or formal speech — think safety guidelines or equipment labels. It’s rarely used in casual conversation where people would simply say 绳 or even 麻绳 (hemp rope) or 尼龙绳 (nylon rope) for specificity.