The point is that the latin prefix re- usually seems to imply repetition whereas the meaning we have for research nowadays is that something new is being sought. … The prefix re- was presumably added in line with the usual treatment of Latin words brought into French.

What is the root word of research?

The word research is derived from the Middle French “recherche”, which means “to go about seeking”, the term itself being derived from the Old French term “recerchier” a compound word from “re-” + “cerchier”, or “sercher”, meaning ‘search’.

How do you know if it is a prefix?

A prefix is a word part added to the beginning of a word that changes the word’s meaning. A suffix is a word part added to the end of a word that changes the word’s meaning.