Definitions:

1. To adjust a scope, instrument, or measurement to be precise or accurate. VERB
   • The technician zeroed in the microscope for a clearer view.
2. To aim a weapon or device accurately at a target. VERB
   • The sniper zeroed in on the enemy position.
3. To focus attention or effort closely on something. VERB
   • The researchers zeroed in on the cause of the disease.

Synonyms:

• aim
• concentrate
• fixate on
• focus
• home in
• range in
• take aim
• target
• zero
• zoom in