This is the 853rd most frequent Vietnamese word.
khai
"Open," "declare," or "begin," depending on context.
Here, 'khai nở' refers to the blooming or opening of flowers.
Mùa xuân hoa mai khai nở khắp nơi.
In spring, apricot blossoms bloom everywhere.
In this context, 'khai thác' means to exploit or utilize resources.
Họ đã tiến hành khai thác tài nguyên thiên nhiên.
They carried out natural resource exploitation.
In this sentence, 'khai báo' means to declare or to provide an official statement.