What is Calibre ?
Calibre is (noun) 1. the measurement across the inside of a gun barrel The two bullets come from same calibre guns. 2. a quality or ability which something or someone has, particularly when it is of a high standard It’s work which he thinks is beneath a person of his calibre. (NOTE: [all senses] The US spelling is caliber.)
source: Easier English, Student Dictionary Upper Intermediate Level