The correct way to write it is best friend. So your answer is two words.An example sentence is: I would like you to meet my new best friend.
best friend
Best friend means "melhor amigo" in portuguese. best = melhor friend = amigo
1. Family 2. Best Friend 3. Best Friend Forever
Yes, the compound noun 'best friend' is a common noun, a word for any best friend of anyone. A proper noun for best friend is the name of the friend, Sofia. The word "friend" in the sentence "Sofia is your best friend" is the only common noun. "Sofia" is a proper noun, "is" is a present-tense verb, "your" is a possessive adjective, and "best" is a superlative adjective.
Common nouns in the sentence "Sofia is your best friend" are: friend, Sofia.
Best friend
you could say ichiban suki na tomodachi (lit. my number one favourite friend)
no one is her best or boy friend
no one is her best or boy friend
One best friend is enough.
Your best friend is the one that you do EVERYTHING with. You can trust them and they can trust you.