One who, or that which, locates.
"The GPS locator helped us find our way through the dense forest after we got lost on the hiking trail."
In plain English: A locator is something that finds and shows you exactly where a specific place or person is.
"The app's locator feature quickly found my friend's house on the map."
Usage: In everyday usage, a locator is an object like a device or map feature used to find a specific position rather than a person performing the action. You typically see this term on GPS screens or treasure maps to mark where something has been discovered.
The word locator comes from the Latin locātor, which originally meant a person who hires out property or services. Although English speakers might analyze it as "locate" plus the suffix "-or," its true origin is this specific Latin term for a provider rather than someone who simply finds something.