[dee-foh-kuh
s] 
verb, -cused, -cus⋅ing or (especially British) -cussed, -cus⋅sing, noun, plural -cus⋅es.| 1. | to cause loss of focus of: The slightest movement will defocus the microscope. |
| 2. | to interrupt or disturb (concentration, attention, etc.). |
| 3. | to disturb the concentration or awareness of (someone). |
| 4. | to lose or go out of focus. |
| 5. | to lose concentration or awareness; become distracted. |
| 6. | the result of defocusing, as a blurred photographic image. |
| de·fo·cus (dē-fō'kəs) tr.v. de·fo·cused or de·fo·cussed, de·fo·cus·ing or de·fo·cus·sing, de·fo·cus·es or de·fo·cus·ses To cause (a beam or a lens) to deviate from accurate focus. n. The act or result of causing a lens to deviate from accurate focus. |