آشنا/ آشنایی

acquaintance  /@"kweIn.t@nts/ noun

 person that you have met but do not know well
a business acquaintance

FORMAL used in some expressions about knowing or meeting people
It was at the Taylors' party that I first made his acquaintance = first met him
I wasn't sure about Darryl when I first met her, but on further acquaintance (= knowing her a little more) I rather like her

  FORMAL knowledge of a subject
Sadly, my acquaintance with Spanish literature is rather limited

have a passing/slight/nodding acquaintance with sth
to have very little knowledge or experience of a subject
I'm afraid I have only a nodding acquaintance with his works