Ear wax is slang for a concentrate with a soft, gooey consistency. The name is descriptive and exactly as unflattering as it sounds.
Where it came from: back when names for the consistencies were still being worked out, things got called after whatever they resembled. Hence also honey, sap or Crumble.
These days it has settled into plain wax , and you will hear ear wax mostly from people who have been around longer. It is the same thing — a soft, sticky concentrate that wants a needle dabber and a silicone jar.