mySQL - remove duplicate rows

hi, Iam writing a python script that gets articles from a MySQL DB, splits the article in its words, gets all synonyms for that word and saves it back to the MySQL server.
the problem now is that there are duplicate synonyms for each article.

Iam using three tables:
articles with aID, article
synonyms with sID, synonym
and a correlation table corr with aID, sID

anyone got an idea how to remove duplicates from the tables synonyms and corr or a tip how to avoid this?

A good tip is: Databases considered harmful, use ndb or plain text files.