noun

• (obsolete) A liar; a deceiver.
• (US, dated) A radio commentator or disc jockey.

noun

• (uncountable, music) A subgenre of hardcore techno characterised by an intense, distorted kick sound and controversial lyrics or samples.
  "This, in turn, birthed all kinds of mainly regional variations that have lasted from the 90s to today, most notably gabber—a relentless mix of superfast BPMS, distorted kickdrums and roared vocals that evoked the distilled nihilism of Rotterdam skinheads."
• (countable) A fan of this music, usually dressed in a tracksuit, often with a completely shaved head (or partially for women), seen primarily in the 1990s.

noun

• (social media) A user of the social media site Gab.
  "In a post on Medium on May 8, Gab leaders shared the latest statistics: "In under nine months, 170,000 Gabbers have 7.6 million posts and raised $145,000 to help us expand our team and cover operational expenses.""