When calling someone Micronesian, you're referring to their origin from the Pacific region of Micronesia. He's Micronesian, hailing from the beautiful islands of Micronesia.
Pro Tip 2/3
Not Just One Place
Micronesia consists of several countries and territories, so a Micronesian may come from any of these diverse islands. Micronesians from different islands may speak various languages.
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Cultural Variety
Remember, 'Micronesian' implies a rich cultural heritage, and aspects vary from island to island. Micronesian dances differ across the region.