Sentence:  I realized a split second too late that for perhaps 70 yards the surface was coated with slime, evidently deposited by farm carts crossing between staggered gates on opposite sides of the road. The car I was driving, not the <WSD>wieldiest</WSD> of vehicles, started to slide. 
Meaning of the word marked with <WSD> tags:  Capable of being easily wielded or managed; handy.