To focus one's aim; to zoom in and center (on something).
The pilot zeroed in on the bunker and launched a guided missile.
To successfully narrow down a search (for).
See if you can zero in on the caller.
To concentrate or focus one's attention (on a task).
One member of the check fraud team will zero in on the fingerprints.
To converge (on).
At the spring sale, everyone zeroed in on the bargain clothes.