What does the phrase "足矣" mean? I saw this phrase recently in a post online. The whole sentence is 人生得一知己足矣. I think 人生得一知己 means "getting a BFF(?) in one's life". (The only meaning of the word 知己 that I know of is BFF, but please correct me if I am wrong!) What does 足矣 mean? Is it a phrase or is it two separate words that just happened to be together in this example?

By the way, is this a phrase used in classical Chinese? The sentence structure looks different from modern Chinese.
足矣 means (lucky) enough.

So the whole sentence means:

knowing a person who understand you (soul mate? I think) in one's life is enough.

Implicit meaning: many people won't have even one soul mate all his/her life. When you have one, you are lucky enough. So please appreciate it and don't ask for more.