What does 'under the radar' mean?

What it means: Going unnoticed - operating or existing without attracting attention or detection. Something "under the radar" is happening but nobody is paying attention to it.

Where it comes from: Military aviation - flying low enough to avoid being picked up by radar systems. The metaphor transferred to everyday life: staying below the level where you'd be noticed or scrutinised.

Two common uses:

1. Deliberate: "They launched quietly, staying under the radar while they built their product." (Intentionally avoiding attention)

1. Accidental: "The mistake went under the radar for months." (Wasn't noticed, not necessarily deliberate)

• "He's been doing great work, but staying under the radar."
• "The new regulation flew under the radar - most companies missed it."
• "Try to stay under the radar until the situation settles down."

• "Unnoticed" - neutral
• "Off the radar" - slightly different: something that was once known about but is now forgotten
• "Below the fold" - media/journalism version (content that isn't immediately visible)
• "Quietly" - when describing intentional low-profile actions

Register: Casual to professional. Works in most contexts.

Tags: idiom, attention, stealth, everyday English, workplace