Meaning

1 senses
  1. (UK, humorous, not comparable, slang)Crazy; mad.

Origin

The term refers to the location of Barking station on the District line of the London Unde

The term refers to the location of Barking station on the District line of the London Underground, which is three stops west of Dagenham Heathway tube station, in allusion to the phrase barking mad.

Wiktionary, CC BY-SA 4.0 · source

three stops short of Dagenham — meaning, examples, forms, synonyms | Krumeto