Detectable means able to be discovered, noticed, or measured. If something is detectable, you can find evidence that it exists, even if you have to look carefully or use special tools.

Scientists look for detectable traces of chemicals in water samples to check if it's safe to drink. A doctor might say that a disease is detectable in its early stages through blood tests, meaning they can spot signs of it before symptoms appear. Security systems can identify detectable motion in a dark room using infrared sensors.

The word often appears in contexts where finding something requires attention or equipment. A detectable smell might be faint but still noticeable if you pay attention. Detectable radiation from a star tells astronomers it exists, even though it's trillions of miles away. When something becomes detectable, it crosses the line from invisible or unknown to something you can actually identify and measure.

The opposite is undetectable: so hidden, faint, or small that even careful searching can't find it. When a submarine tries to stay undetectable, it's working hard to avoid leaving any detectable signs of its presence.