I need help with these definitions! Thanks!! Just some or all would be nice!!

Cyrus the Great
Zoroastrianism
Sparta & Athens
Peloponnesian War
Macedon
Philip of Macedon
Alexander the Great
Hellenism
Hellenistic culture
Carthage & Punic Wars
Julius Caesar
Augustus
Constantine
Polis
Pericles
Roman Senate & Consuls
12 Tables
Greek Pantheon of Gods
Socrates
Plato
Galen
Euclid
Ptolemy
Iliad & Odyssey/Homer
Doric, Ionic, Corinthian styles

3 answers

A lot of these can't really be 'defined', but a very good website where you can find a general idea of what these things are is the Enyclopaedia Britannica website.

I hope this helps (:
The Encyclopedia Britannica charges for its complete articles.

Sra's suggestions are free.
It does charge for complete articles, but it does have a short brief which is free. For a very general idea of what you are looking for, the Encyclopedia Britannica is fine.

Sra's suggestions are very good, though.