As to your definition guestion. Wikipedia has it pretty good:
As to reefing a jib, you should be able to partially furl a jib the same why you completely furl it at the end of the day, just roll it only part way. Most partially furled jibs don't provide very good sail shape but the smaller area can reduce the forces generated a lot.
If this is a 130%+ sail, you might be better off in those winds furling the whole thing and sailing with just your main.
If your having trouble with your furler in a breeze you should see if you can dig up whatever instructions came tihwt that unit. In short, to furl in a breeze release enough of the jib sheet so you can take in the furling line by hand. You should always keep some sheet pressure on the sail so that it furls tighthly (otherwise a sail can be subject to being opened in a storm). If you cannot haul int he furling line by hand, or the halyard wraps, then something is wrong with the furler. There are a number of Saiilnet threads as to what can go wrong with a furler, you can search for those.
Get on the Catalina email list and see what has worked for other owners of that boat.