RE: glider vs sailplane
So in RC if you say "I'm bringing my sailplane/glider" We know what you mean.
Now as to what kind of sailplane/glider you get into
hand launch
discus launch
thermal
scale
electric
motor
slope sorer
So when talking to non-RC folk you can say "I have a sailplane/glider"
When talking to RC guys use the sub category that describes exactly what your talking about. "I just put the covering on my discus glider" or "I crashed my sloper yesterday".