Lisa's dictionary is different from widely-used real dictionaries. Here's what Merriam-Webster says[1]:
Some assert that only envious is correctly used to describe someone who feels or shows a very strong desire for something that belongs to someone else, but in truth both envious and jealous commonly carry this meaning. Jealous alone is used to describe someone who tends to suspect unfaithfulness.
They may be equivalent in common parlance, but that’s a bit like saying it is ok to use ‘your’ instead of “you’re” just because it is so common.
We say “jealously guarded’ not ‘enviously guarded’ for a reason. Jealousy is about being protective of your own possessions and relationships; you feel jealousy if your spouse responds well to a coworker’s flirtations. Envy is when you find think of the coworker’s luck in having a good looking spouse
If you check "jealousy" (instead of "jealous") on MW, you get this editorial note:
Depending on who you ask, jealousy and envy are either exact synonyms, totally different words, or near-synonyms with some degree of semantic overlap and some differences. It is difficult to make the case, based on the evidence of usage that we have, for either of the first two possibilities. Both jealousy and envy are often used to indicate that a person is covetous of something that someone else has, but jealousy carries the particular sense of “zealous vigilance” and tends to be applied more exclusively to feelings of protectiveness regarding one’s own advantages or attachments. In the domain of romance, it is more commonly found than envy. If you were to say “your salt-shaker collection fills me with jealousy,” most people would take it to mean much the same thing as “your salt-shaker collection fills me with envy.” But if someone made a flirtatious comment to your partner, you would likely say that it caused you jealousy, not envy.
Homer explains it best https://youtu.be/Tmx1jpqv3RA