One of the oldest criticisms of the Catholic Church is that by giving reverence to saints, we are practicing idolatry. This is not true, of course. We do not worship Saints, but we do venerate them.
The definition of veneration is “to revere or regard with great respect”. “I pray thee” is an archaic English phrase meaning simply meaning “please”. It was frequently used in literature, particularly during the Shakespearean era, as a formal, polite, or emphatic way to ask for something: “I pray thee” was the equivalent of the modern “I beg of you”.
Pope Benedict XIV put it this way:
“Veneration of a human being must in no way be confused with the adoration shown to God alone. We see at the end of the Old Testament, for example, what veneration pious Jews paid to their great forefathers, the patriarchs, Moses, and the prophets without thereby offending in the least against the worship owed to God.”
Unfortunately that distinction can become blurred….you may hear someone say “I prayed to Saint so-and-so”….but what they actually mean is that they implored that saints’ intercession.