I’m new to the IF scene, and I’m seeing this term pop up now and then but I can’t find a definition. Unfortunately, it’s also too short of a query for the search-engine 
I’m gathering that it might mean “long-term interest”? But I want to be sure so that I don’t go around using terminology incorrectly!
LI is usually used for Love Interest. RO (Romantic Option) is more commonly used, i think
Well, I was going to say someone tried to type “Lol” and missed out the O, but that could be it too. 
It mean Love Interest, it’s not often used here because RO is better to describe the different character you can romance