noun
prehistoric age; previous world
Refers to the world or era before recorded history, or a previous geological/biological age. Often used in scientific or historical contexts.
前世界の生物について研究している。
I am researching organisms from the prehistoric age.
この化石は前世界のものだ。
This fossil is from a previous world.
古代 refers to ancient times (often historical), whereas 前世界 refers to prehistory or a world before the current one.
Compound of 前 (before) and 世界 (world). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning 'prehistoric age' or 'previous world'.