Don't know what it means, but "CB" designates "street bike".
Starting from the early 1960s:
The "CL" moniker designated "dual purpose".
The "SL" moniker designated "sport scrambler".
The "CR" was for racing.
The "CX" designated "limited production experimental" bikes. The 500 and 650 V-twin were in this category, both of which Honda underestimated demand, like the CB750K model.
The "CBX" was limited production, high-performance, streetable bikes.
Somehow, "GL" became touring.
Doesn't seem to fit with the others, does it?
Then, in 1979 or so, all sorts of designators appeared for a while. Now, some of the old ones are back again.
Beats me what it means.