Vainglorious
Definition: excessive pride in one’s accomplishments
The root is “vainglory,” which is clearly just a compound word of “vain” and “glory.”
Why I Looked It Up
From The Library:
By 2010, Google had calculated, with vainglorious precision, that 129,864,800 books had been published since Gutenberg.
Postscript
Added on
In The Swerve: How the World Became Modern, a figure during the Italian Renaissance says:
May I be kept from taking pride in dreams of self-exaltation of vainglory.