- (metrology) Symbol for the terajoule, an SI unit of work or energy equal to 1012 joules.
- The ISO 3166-1 two-letter (alpha-2) code for Tajikistan.
- Symbol for a Jeep Wrangler  1997-2006 model.
- Tijuana (a city in Mexico just south of the American border)
2016, Mike Salazar, Steak & Cherry Pie:
- That was when Customs stopped every car at the S. D. border and checked for drugs, which reminds me of the first time I went to TJ—Tijuana, Mexico.