well it can be thought as brave+witty and CONCISED into brevity or it can be similar to brief
brevity sounds like levity which means lightness..when something is light it means it is short and concise..
Think BREath , VITamin. You take deep BREATHs trying to survive in a pit full of VITAMINS. You inhale more and more vitamins causing your life to be very BRIEF.
Brevity = br( brave) + evity (evidence); brave evidence describes everything in brief.
Rhymes with Gravity..when we fall under gravity..the fall is free fall and is short period of time.