Arcane and Unnoted

Arcane adjective - Difficult for one of ordinary knowledge or intelligence to understand.

Unnoted and arcane are semantically related In some cases you can use "Unnoted" instead an adjective "Arcane".

Unnoted adjective - Not taken into account.

Arcane and unnoted are semantically related in out-of-the-way topic. Sometimes you can use "Arcane" instead an adjective "Unnoted".