Learner's definition of ACQUAINTANCE
1 [count] : someone who is known but who is not a close friend
Is he an acquaintance of yours? [=have you met him?]
She ran into an old acquaintance at the grocery store.
My wife and I met through a mutual acquaintance. [=a friend introduced us to each other]
a casual acquaintance
friends and acquaintances
2 [noncount], formal : the state of knowing someone in a personal or social way: the state of knowing someone as an acquaintance
our family's close acquaintance with our neighbors
It's a pleasure to make your acquaintance. [=(less formally) it's nice to meet you]
She made the acquaintance of [=she met] a man from the city.
She struck up an acquaintance with a man from the city.
a doctor of my acquaintance [=a doctor that I know]
He seemed cold on/at first acquaintance [=when I first met him], but later I realized that he was just shy.
He seemed cold at first, but on closer/further acquaintance I realized that he was just shy.
3 : knowledge about something— + with
She has only a nodding/slight/superficial acquaintance with the facts of the case. [=she knows only a little about the facts of the case]
He has more than a passing acquaintance with wine. [=he knows a lot about wine]