1. a person or device that focuses or brings something into focus
Usage: commonly used in photography, optics, and general contexts
2. a person who concentrates attention or effort on a particular task or goal
Usage: informal usage

Examples

• The camera's autofocuser adjusted the lens to capture a sharp image.
• She is a natural focuser who can block out distractions and complete her work.
• The microscope's focuser allows precise adjustment of the specimen's clarity.
• As a focuser on detail, he caught errors that others missed.
• The photographer relied on the manual focuser to achieve the desired depth of field.