Okay. A simple definition. Since you are either incapable or unwilling to come up with one yourself.
Secularism as I understand it, on a state level is separation between state power and any bias or preference of any religion. That does NOT mean that it does not allow religion to be practised and preached freely. On an individual level, secularism is an openness and tolerance of all thoughts on matter of religion, without the need to internalise the opinions and beliefs or others. Secularism is NOT a substitute for religion, nor does it exhibit religious 'beliefs' of any sort, it is instead a set of loosely defined ideals.
Please give me a critique of this definition, and spare me any rant about your preconceived notions about religion and society.