The man is her beloved and her friend. It is the only time she uses the term friend
to refer to him and it is as if the prospect of losing him has helped her to truly discover what he means to her.
The woman's description of the man in Song of Solomon 5:10–16 more than answers the question that the daughters posed to her in Song of Solomon 5:9.1
16 His mouth is most sweet, and he is altogether desirable. This is my beloved and this is my friend, O daughters of Jerusalem.