Half-know

An individual with whom you have a interesting relationship: This relationship ranges from having seen the pereson now and then, to being meagerly acquainted (as in, having been introduced at one time, say a year ago) with them. Different from an acquaintance, half-knows are often avoided when seen in real life, as meeting with them can be excruciatingly awkward, particularly if the half-know does not recognize you.

Jim: "Hey, Tom, you see that guy over there?"

Tom: "Yeah, what about him?"

Jim: "I've seen him a hundred times at work, but I've never talked to him. Kinda weird, huh?"

Tom: "Don't let him see you; he's a half-know!"