The phrase ‘under the radar’ is commonly used to describe something that goes unnoticed or undetected. It originates from military terminology, where it referred to aircraft flying low enough to avoid detection by radar systems. In everyday language, it means to do something without attracting attention or to remain unnoticed.
For example, if a small startup company is growing quietly without much media coverage, you might say it is operating ‘under the radar.’ Similarly, if someone is working on a project without others knowing about it, they are keeping it ‘under the radar.’
This expression is often used in both personal and professional contexts to describe actions or events that are intentionally kept low-key or unnoticed.