An explanation of the term "marry" in myShakespeare's Romeo and Juliet, Act 1, Scene 3
Nurse
On Lammas-eve at night shall she be fourteen;
That shall she. Marry, I remember it well.
'Tis since the earthquake now eleven years,
“Marry” is a reference to Mary, the mother of Jesus. The nurse uses it as a mild oath to add intensity to her statement, just as we might say "indeed" today.
