In short, I would describe corruption as “the slavery of power and passion over one’s rationality”. In other words, a corrupted person would commit deeds not out of rationality or morality, but simply because they blindly obey their passions without inflicting any doubt on them.
Every corrupted person would commit corruption because of putting their passions as their prime authority, over the authority of law and justice. I dare to say that this principle goes beyond politics or criminal activities, but would also be described as such in every other field which creates addiction, an addiction or a set of them that overcome rational and logical thought. Therefore, not only people with large authority can be corrupted, but also the common people, which corrupt their health in the name of enjoying alcohol, smoking, unprotected sex and so forth.
Corruption is the impurity of a situation or entity, from being relatively pure or completely pure, into a depth of abusing, harming, betrayal and manipulation. Therefore, addicts are also corrupted, because they let their passions which grant them happiness and satisfaction, also harms them and the people around them. The notion of harm by corruption is also present in politics.
However, some corruptions are natural. Those who lose their childlike innocence become mature by the corruption of their childish purity, which is caused by experiencing life. Making your teeth dirty is also a form of corruption, even though it is only a result of eating, which is necessary for one’s survival.
Just because some corruptions are natural, it does not mean some of them should be overlooked. It is of the human nature to be corrupted by the impurity of life and society, and be prone to temptations by said life and society. It is of human nature to enjoy ourselves and what we have, without or minimally caring about the harm that said joy can cause us. Just like the alcoholic wishes for more alcohol, the corrupted politician wishes more money and power, and just like an alcoholic would ruin his health by their addiction, the corrupted politician shall betray the morals of their profession and commit crimes for the sake of more money and more power, which in return shall fulfill their passions for the short term, until the inner monster that is lust torments them to damage themselves, whether by health or reputation, in the name of filling the demand of their suffocating passion. A candy is no different than from political power: you may be tempted to want more and more of them.
This is why corruption is the slavery and the incitement of passion against one’s rational security: it is an inner bully we are thought by society that it is best to fulfill that bully’s demands. And so, we believe that that bully is the source of our beings and the meaning of our lives. How pathetic.
Regarding the second part of this question - no. its definition shouldn’t be changed to the present context, because corruptive tendencies are a part of our primitive nature, and always have been as such. What we should do is to be more rational, because rationality is there to protect ourselves from external an internal threat which can harm, if not destroy, us in the long-run.
As we consume more and more addictions, regardless of what authority we have in our hands, we slowly begin to lose the most vital authority, which is our authority over ourselves. We lose our sense of morality and the condition of our health and our reputation in the name of non-submissive passion.
Overcome your passion and restrain it, and you shall be cleaner from the dirtiness and poison that is corruption. Learn to distinguish between the rational self, which is you, and between the passionate self, which is like a dog that needs to learn it lessons constantly until it submits to their master - to you. A corrupted person is always a slave, and sadly our culture is one of slavery, and not of mastery. By filling our passions on a constant basis, we lose our liberty in the name of the primitive parts of our consciousness, and thus we also lose our individuality and submit to the hedonistic herd mentality.
You still have a chance to save yourself from the addictive corruption regardless of who you are and what it is that you’re addicted to, as we all can by looking beyond our emotions and urges, into a more clarified vision of optimal purity. Save yourself from the tyrants of immediate pleasure, for you are not a blind animal, but the ruler of the world - the human being, which may be the only being that can overcome themselves with the gift of logical clarity and meta-cognition.
May you become your best self; a self-pure from the leash of harming primitivism under the fake mask of rewarding joy; a rational self.