* As an ordinal number: "El segundo día" (The second day)
* As a unit of time: "Un segundo" (One second)
* As a noun meaning "second" in a sequence: "El segundo lugar" (Second place)
* As an adjective meaning "secondary" or "second-rate": "Un producto de segundo orden" (A second-rate product)
It's important to consider the context to understand the precise meaning of "segundo".