未知

1. Origins, structure, and basic meaning

• Structure: 未知 (みち) denotes what is not yet known or experienced.
• Basic usage: It most often modifies a noun with の, as in 未知の洞窟 or 未知の現象.

2. Common pitfalls and similar expressions

• Not yet known
  • It suggests something not yet established by knowledge or investigation, rather than a momentary lack of recall.