αιώνας

From Ancient Greek αἰών (aiṓn, “epoch”).

αιώνας • (aiónas) m (plural αιώνες)

1. century (100 consecutive years)
2. century (specifically a numbered period with conventional start)

   Έγινε στα μέσα του 20ου αιώνα. ― Égine sta mésa tou 20ou aióna. ― It took place in the middle of the 20th century.

3. (geology) eon, era, age

   Φανεροζωικός αιώνας ― Fanerozoikós aiónas ― Phanerozoic eon

4. eternity, age, eon

• (century): αι. (ai.), αι (ai) (abbreviation)
• (eon): μεγααιώνας m (megaaiónas) (geological timescale)
• (100 consecutive years): εκατονταετία f (ekatontaetía)

"Proterozoic eon" will be found translated as "Προτεροζωικός αιώνας" and "Προτεροζωικός μεγααιώνας". The form "αιώνας" can mean any long period (age, century, etc) so "μεγααιώνας" - large eon - is often used to make the meaning clear.

• αιώνια (aiónia, “forever”)
• αιώνιος (aiónios, “eternal, perpetual”)
• αιωνιότητα f (aioniótita, “eternity”)
• αιώνιως (aiónios, “forever”)
• αιωνόβιος (aionóvios, “long-living”)

• see: έτος n (étos, “year”)