People who care about their data and their business know what they mean.
Although, at my particular shop, we use the term "BC" instead of "HA".
BC = Business Continuance (HA = High Availability)
DR = Disaster Recovery
BC = "Looks like we just lost a drive in the array. Better replace that right away." or "Oops, broke one of the multiple fibers to the SAN. Where's the spare again?"
BC also applies to our load-balanced clusters of web servers and application servers that allow for the offlining or loss of entire machines without losing functionality. You need more than your data existing on media to Continue Business - you and your customers need to be able to GET to it somehow.
DR = Your building just burned to the ground, taking every single piece of furniture, equipment, paper, and magnetic media inside along with it. Now what?
Please note that the coolest, slickest, snapshotted NAS with terabytes and terabytes of awesome cheap SATA storage in it is worth exactly JACK in this scenario if it's in the same building as the source material. Offsite backups are not optional, and offsite storage of hard drives isn't exactly the easiest thing to do.