即ち

1. Origins, structure, and basic meaning

• Structure: 即ち is read as すなわち and is a connective adverb that restates preceding information more explicitly or identifies its direct implication.
• Basic usage: Place it between propositions, as in 立入禁止、即ち中へ入れない, or before a phrase that defines what a preceding choice amounts to.

2. Common pitfalls and similar expressions

• Not temporal immediately
  • Here it means that is, namely, or in other words; it does not describe an action happening at once.
• Preserve its discourse function
  • Even when a sentence remains grammatical without it, omission loses the explicit restatement or identification carried by 即ち.