is it on your iphone? i have one or two of those as well. try entering this chord, your basic g there, with just one extra note added, and see how many additional descriptions it comes up with...
the 'no 5' means 'no 5th in the chord'. and just about any chord you care to mention can be 'named' in at least one other way.
naming of chords is, just about, always relative. it has to do with where and in what key you're playing it, among other things. that is just about as much as i can go into now, without getting into too much detail. just enough to confuse you, without confusing myself.
good luck, feel free to ask more and i'll try my best to answer. whatever i can't, someone else here will be able to, i'm sure.