1. A shape of tomato, which is typical of large tomatoes. Not quite round. It need not belong to a large tomato (i.e. Menehune is a small beefsteak-shaped tomato).
2. There is an actual breed of tomato called Beefsteak, which is said to be synonymous with Fejee Improved, Crimson Cushion, and/or Ponderosa Red.
3. A large, beefsteak-shaped tomato (e.g. Brandywine, Cherokee Purple, etc.)
4. A certain type of firm, slicing tomato.
Surprisingly, people don't actually call steaks beefsteaks, as far as I know!