verb (used with object), de·fo·cused, de·fo·cus·ing or (especially British) de·fo·cussed, de·fo·cus·sing.
- to cause loss of focus of: The slightest movement will defocus the microscope.
- to interrupt or disturb (concentration, attention, etc.).
- to disturb the concentration or awareness of (someone).
verb (used without object), de·fo·cused, de·fo·cus·ing or (especially British) de·fo·cussed, de·fo·cus·sing.
- to lose or go out of focus.
- to lose concentration or awareness; become distracted.
noun, plural de·fo·cus·es.
- the result of defocusing, as a blurred photographic image.