die Bekanntschaft
acquaintance
A person you know but are not close friends with; a male or female acquaintance.
Er ist nur eine flüchtige Bekanntschaft aus dem Studium.
He is only a casual acquaintance from university.

acquaintance
Loading your saved state.
acquaintance
A person you know but are not close friends with; a male or female acquaintance.
Er ist nur eine flüchtige Bekanntschaft aus dem Studium.
He is only a casual acquaintance from university.

The word belongs to the family of 'kennen' (to know) and 'bekannt' (known / familiar). The ending '-schaft' often forms nouns that describe a relationship or a state, as in 'Freundschaft' (friendship).
Unsere Bekanntschaft begann auf einer Konferenz.
Our acquaintance began at a conference.
The most common use is the fixed expression 'Bekanntschaft machen' (to make someone's acquaintance). It means 'jemanden kennenlernen' (to get to know someone) and is often used with the preposition 'mit' and the dative.
Ich habe im Urlaub die Bekanntschaft mit netten Leuten gemacht.
I made the acquaintance of some nice people on vacation.
When 'Bekanntschaft' (acquaintance) describes a person, it is often combined with adjectives such as 'flüchtige' (casual), 'neue' (new), or 'alte' (old) to characterize the type of relationship.
Er traf eine alte Bekanntschaft aus seiner Schulzeit wieder.
He met an old acquaintance from his school days again.
friend / boyfriend
'der Freund' and 'die Bekanntschaft' both describe a person you know. The important difference is closeness. A 'Freund' is someone with whom you have a close personal relationship and whom you usually trust. A 'Bekanntschaft' is someone you know, but not especially well or not very closely. The word can also mean the loose relationship itself. Learners may confuse the words because both belong to the area of social contacts. If the relationship is important and personal, 'Freund' fits. If the contact remains rather casual, 'Bekanntschaft' fits.

Mein Kollege ist nur eine Bekanntschaft aus dem Sprachkurs.
My colleague is just an acquaintance from the language course.
Mara bringt am Samstag ihren besten Freund zur Feier mit.
Mara is bringing her best friend to the party on Saturday.