This is the 853rd most frequent Chinese word.
康
"康" means "health" or "well-being."
In this sentence, '康' is used as a part of a proper noun, the name '康娜'.
她的名字叫康娜，非常可爱。
Her name is Kang Na, and she is very cute.
Here, '康' is used as part of the adjective '健康', meaning 'healthy'.
他身体健康，一直坚持锻炼。
He is healthy and has consistently been exercising.
In this example, '康' appears as part of the noun '安康', meaning wellness or health.