1. to cause to lose focus or sharpness; to make blurry or unclear
Usage: photography; optics
2. to shift attention away from something; to lose concentration on

Examples

• The camera automatically defocuses when the subject moves too close.
• Poor lighting defocuses the image and makes it hard to see details.
• The loud noise defocuses her attention from the book.
• He defocuses from his work when his phone buzzes.
• The photographer intentionally defocuses the background to highlight the subject.
• Stress often defocuses students during important exams.