1. In modern times, "taboo" means: avoid breaking taboos; Often extended to: deliberately avoid something or someone. In ancient times, "taboo" means: you can't directly say (write) the names of the monarch or relatives.
2. Synonyms of "taboo" are avoidance, taboo, taboo and taboo.
The antonym is: call a spade a spade. "Taboo" comes from Liu An's A Brief Introduction to Huainan Zi.