Jealousy ( \JEH-lə-sē\) is defined thus: 1 : a jealous disposition, attitude, or feeling; 2 : zealous vigilance. Ooh, I like that second one - zealous vigilance. You may have guessed, but not known that jealous and zealous are relaated. In fact, they're the same word, just "tweaked" a little through Middle French for that coolest of letters, the 'j'. My own twist on the definition may make my own prejudices more clear: Jealousy is the deep passion a person feels for that which belongs to that person. Jealousy is the desire you feel for that which is yours because it is yours. It is patriotism on the personal level. A modern world leader once remarked in a disgust in any person "who could say they love their country, and hate their government." A strange sentiment for someone from the Central Southern US, a region well-known for jingoistic cheerleading for "America" - or the local school football team, depending on the time of year you ask (not trying to be insulting here - almost all of my family lives in "the South").
Anyway, to me, jealousy means that you hold your things and people in high regard, not because they're better than anyone else, more virtuous, richer, prettier or more powerful. Jealousy means you love what's yours because it's yours, or rather, because you are theirs. Jealousy also means you don't let your object of passion go off in a state of abandonment. If it's yours, you take care of it, and keep it from molestation by foreign hands - foreign in this sense being anyone who shouldn't be there, including greedy cousins with too much of a sweet tooth...but I digress.
Jealosuy isn't only accusing someone of falsely seeking to betray you. Jealousy is about looking to give the best, and to be the best, to those you love. Now, is that something the world could use more of, or what?