The meaning of the prefixes as used in their word context are;
Over cast - Above head.
infra structure-Within
Per meter - For each
Post pone - Push forward
Octa gon - Eight
Hyper active - Super/Over
Pre pare - Prior
Ex-clude - Exempt
Sub merge - Put within
Syn chronize - together
<h3>What is a prefix?</h3>
A prefix by definition is an affix which is placed before the stem of a word, which in most cases denotes meaning on its own. However, upon addition of the prefix to the beginning of one word, the word changes it into another word.