In wow, before they streamlined their stats, critical resistance came from the defense skill. Tank characters who had a defense skill a certain number of points above max level would be completely immune to critical hits, and being a good tank involved stacking gear that had the defense stat on it to reach this breakpoint.
That's different than armor or block value. Defense was like a weapon skill, which leveled by being hit. They have since removed that, and made most stats more streamlined, to the point where simply being a tank class makes you crit immune.
I doubt this information helps you out much, as 'defense' is a poor choice for the name for critical evasion.
As an actual suggestion, I'd go with Critical Resistance, but if Critical Evasion sounded too clunky for you, that's probably even worse.