How To Spell caliber, calibre?

Correct spelling: caliber, calibre

What is the definition of caliber, calibre?

  1. The diameter of a canal, such as the esophagus or urethra.

Google Ngram Viewer results for caliber, calibre:

This graph shows how "caliber, calibre" have occurred between 1800 and 2008 in a corpus of English books.