深度 (shēn dù) literally combines 深 (shēn), meaning 'deep', and 度 (dù), meaning 'degree' or 'measure'. Together, it denotes the physical depth of something — like water, a wound, or a hole — but more commonly functions abstractly to express the degree or extent of a quality: how profound, intense, serious, or thorough something is. It’s frequently used in academic, medical, technical, and everyday contexts.

You’ll encounter 深度 in phrases like 深度学习 (shēn dù xué xí, 'deep learning'), 深度睡眠 (shēn dù shuì mián, 'deep sleep'), or 深度分析 (shēn dù fēn xī, 'in-depth analysis'). Unlike the standalone adjective 深, which can mean 'deep' or 'profound' on its own, 深度 is always a noun and must be followed by a classifier or measure word when quantifying physical depth (e.g., 两米深, not *两米深度), or paired with verbs like 有, 达到, or 进行 for abstract usage.