pointy
Having a sharp tip that comes to a point.
Pointy means having a sharp end or tip that comes to a point. A pencil is pointy, a witch's hat is pointy, and a cat's ears are pointy. The opposite would be something blunt or rounded, like the eraser end of that same pencil.
You can describe almost anything with a point as pointy: a mountain peak, an icicle hanging from a roof, a thorn on a rosebush, or even someone's nose if it comes to a distinct point. The word has a casual, everyday feeling to it. Scientists might describe something as “pointed” or “acute,” but most people would just say it's pointy.
Sometimes pointy things are dangerous (like the pointed end of a knife) and sometimes they're just sharp enough to be useful (like the point of a pushpin). When you're describing something as pointy, you're usually drawing attention to that sharp tip, whether you're warning someone to be careful around it or just noticing its shape.