Example sentences:

Ramayana: When Angada challenged the demons to budge his foot, that challenge was not his vainglory; it was his confidence in Rama’s glory, for Rama would make his devotee’s foot immoveable.  

Mahabharata: The incidents that Karna presented as evidences of his bravery, Bhishma downplayed as mere expressions of vainglory. 

Bhagavad-gita: The vainglory of demonic people makes them believe that they are greater than God because God’s devotees come to them for charity.