What is the meaning of -ion?

An action or process, or the result of an action or process.

A state or condition.

An anthropometric reference point.

Especially craniometric points

Together with apo- and peri-, forms names of specific apoapsides and periapsides.

-ion

-ion

alternative form of -ien (“-ian”)

alternative form of -ioun

-illion (used to form multiples of 1000: balion «million», telion 1.000.000.000, kilion 1.000.000.000.000)

Pluralisation suffix

Noun suffix

Source: wiktionary.org