sensitive; alert; aware; susceptible
quick-witted and agile; keen and nimble
clever; shrewd; canny; smart; quick; prompt
nervousness; oversensitivity
intelligence; discernment
quickness; agility; activity
quick to seize an opportunity
slowness; inertness; inability; lack of talent; dullness
nimble; agile; quick; quick (thinking); smart; alert
sharp (mind); keen; acute