1. plural of micrometer: units of length equal to one millionth of a meter
Usage: scientific measurement
2. plural of micrometer: precision instruments used to measure very small distances or thicknesses
Usage: engineering; machining

Examples

• The bacteria measured only a few micrometers in length.
• Human hair is typically 50 to 100 micrometers in diameter.
• The machinist used micrometers to ensure precise measurements.
• Dust particles smaller than 10 micrometers can penetrate deep into the lungs.
• The technician calibrated the micrometers before beginning the quality inspection.
• Cell walls are often measured in micrometers rather than millimeters.