A Filipina friend used this word to describe me when she and I were in an odd quasi-relationship a couple years ago and it has stuck with me all this time but I’ve forgotten what she told me it meant… can a tagalog speaker enlighten me? Is it a straightforward word or does it mean more than one thing?
Well, I don’t speak it, but most of the usages I see are for flirting. Words containing the root “-landi-” have to do with flirting, horniness, trampiness, etc., and kalandian is the general word for flirtiness. When used to refer to a person, it appears to range from “platonic friend that I flirt with” to “short-term fling not to be taken seriously” to “f*ckbuddy.” It’s about as well-defined as your relationship. 
Well, she used it to introduce me to her sister and, unfortunately, it never evolved into a physical relationship – it was online and it petered out when she had to go back to university – so I’m guessing she meant it to mean “platonic friend that I flirt with” although “short-term fling not to be taken seriously” could have applied too as we had a very teasing relationship and had have vague ideas of trying to meet despite the thousands of miles between us.
Thanks, Nametag.