Triskaidekaphobia
Triskaidekaphobia ( TRIS-kye-DEK-ə-FOH-bee-ə, TRIS-kə-; from Ancient Greek τρεισκαίδεκα (treiskaídeka) 'thirteen' and Ancient Greek φόβος (phóbos) 'fear') is fear or avoidance of the number 13. It is also a reason for the fear of Friday the 13th, called paraskevidekatriaphobia (from Greek Παρασκευή (paraskevi) 'Friday', Greek δεκατρείς (dekatreís) 'thirteen' and Ancient Greek φόβος (phóbos) 'fear') or friggatriskaidekaphobia (from Old Norse Frigg 'Frigg' and from Ancient Greek τρεισκαίδεκα (treiskaídeka) 'thirteen' and Ancient Greek φόβος (phóbos) 'fear').