"Max Weight"

What do people base this off of, when they're going on, for example. Max Bench 220: Is that, max weight you can do a set of? Is that max weight you can do 1 time?

I mean, if I often worked out at say 150 pounds and I could do a full set, but I could Bench 185 once, maybe twice, would I say my Max Bench is 150, because that's what I can do full sets of, 165, because I can do half a set, or 185 because I can do it once or twice?