Tendency, habit, custom, way of living or acting, shape, usage, virtue or practice. The three terms Sila, Samadi and Prajna are the Three Higher Trainings of Buddhism. Sila is ethics.
There are a lot of ways to interpret Sila. Do not use the word morality here, which is how many people translate it. Morality is completely subjective. What is moral in this country, is immoral in another country. What is moral in this culture, is immoral in another culture. What people in this group over here consider moral is considered immoral by us. So morality and immorality are completely subjective and have nothing to do with the laws of nature.
Ethics on the other hand are objective; they are universal. Violence is harmful. Anger is harmful. This is universal. Selfishness is harmful. This is universal. So this is what we mean by ethics.
Sila is about learning about our tendencies, habits, customs, ways of living, recognizing the ones that cause us to suffer and others to suffer, and starting to change them. That is how we learn to start meditating.
So the first thing is to start watching ourselves, all the time, and be honest with ourselves about what we see in ourselves.