Gumption is a quality that some people have to always take the lead in decisions and situations. People who have *gumption rarely wait for things to happen. They are always fighting to achieve their goals, to get their plans moving and to have their opinions and interests accepted.
*Gumption doesn't have a plural form.
Note: This reminds me of a dialogue from the movie "The Holiday":
Jasper: What exactly has gotten in to you?
Iris: I don't know [pushes jasper out the door] but I think what I've got is something resembling, Gumption! [slams door shut]