That operates to produce an effect.
Any of a class of behaviors that produce consequences by operating (i.e., acting) upon the environment.
An operative person or thing.
Prepared for immediate action or use.
Not slow or hesitating; quick in action or perception of any kind.
Offering itself at once; at hand; opportune; convenient.
Inclined; apt to happen.
Liable at any moment.
ready money; cash
To prepare; to make ready for action.