G5921 - Strong's Greek Lexicon Number


World, Age.
See Definition for aion { [G165]}
See Definition for kosmos { [G2889]}

It is only in a part of their meanings that these two words are in any
real sense synonymous, and it is that part which is here considered.
Both A.V. and R.V. often translate aion by world, thus
obscuring the distinction between it and kosmos. aion is
usually better expressed by age, it is the world at a given time, a
particular period in the world's history.

kosmos has very frequently an unfavorable meaning, denoting the
inhabitants of the world, mankind in general, as opposed to God. A
similar meaning is often attached to aion, it means the spirit of
the age, often in an unfavorable sense. See Eph 2:2, where both
words occur together. An exceptional meaning for the plural of aion
is found in Heb 1:2 11:3, where it denotes the worlds, apparently
in reference to space rather than time.