Under the radar is a phrase used to describe something that is not noticed or seen by others. It can refer to a person, object, or event that is not widely known or recognized. The crossword solutions for this term are LOW (3 letters), STEALTHY (8 letters), and UNNOTICED (9 letters). LOW implies that something is not very visible or prominent, while STEALTHY suggests that it is done in a secretive manner. UNNOTICED implies that it is not seen or noticed by others. All three words together paint a picture of something that is hidden or kept out of sight.