This is the 219th most frequent Vietnamese word.
rõ
Clear; obvious; clearly.
Here 'rõ' is used as an adjective meaning 'clear', describing the clarity of the sound.
Âm thanh này không rõ.
This sound is not clear.
Here 'rõ' is used as an adverb implying the clarity with which the subject perceives or understands the action or idea.
Tôi thấy rõ ý định của anh ta.
I can clearly see his intention.
In this sentence, 'rõ' is combined with 'ràng' to form 'rõ ràng', an adverb meaning 'clearly', modifying the verb 'speak'.