Acquaintance

Etymology

From Old French acointance, from acointier "to make known," from Latin accognitare, from ad- plus cognoscere "to get to know." The word marks exactly the threshold of knowing-of without deep knowing.

noun · /uh-KWAYN-tuhns/
A person you know slightly, with whom you have no real closeness.
What it names
A precise handle for the vast middle tier of social life — the many people we know but are not close to, whom we lack a clean word for and so mislabel as "friends."
Example
They were work acquaintances for years before a delayed flight turned them into actual friends.
Related idea
Distinct from friend: an acquaintance is defined by the absence of intimacy, obligation, and disclosure that friendship carries. The modern habit of calling everyone a "friend" erases this tier — and with it the honest recognition that most of our web is acquaintance, which is no insult.