Fancy church Latin, not Italian. Con in this case means a "This" or "The" - note the caps. Think the declension of clavus (nail) and deus (god) are due to that. Not sure - only 3 years Latin over 20 years ago. So...
This Nail, This God... or maybe if I have that declension of God wrong... This sounds way cooler
"This nail (is) for This God"
conclavi con Dio in Italian means conclaves with God.
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