According to netizen D.H. Bianchi, this term refers to several things:
(2) grating, out-of-tune music;
(3) bad vibes or bad blood between two or more people, or between a person and some aspect of western civilization;
(4) ill feelings stemming from a small incident or misunderstanding (for example, "It turned out the nar was caused by something I said that I meant to be funny but she took seriously");
(5) ensuing trouble created when one doesn't resolve conflicts or when one tries to restrain his true feelings (for example, "He didn't want to rock the boat, so he kept quiet; but in the long run, keeping quiet created worse nar than anything he might've said");
(6) a disturbing atmosphere that appears after an event or encounter (frequently in distinct contrast to what one feels during the occurrence) or something that goes unnoticed at the time but comes to dominate in the end (for the worst);
(7) mysterious energy that produces "that sinking feeling" for no apparent reason (like when someone tells you to "try again").
NetLingo Classification: Online Jargon