“self-se·lec·tion__?n._the action of putting oneself forward for something.” This explaination is very confusing,ask for help

Poor definition. Self-selection is a noun. A verb is about action. Not a very common word. To select means to choose. He selected a better dictionary. In this case selected is a verb. (action) Self-selection (n) 1. Selection of or by oneself. 2. Selection of merchandise by oneself from a display counter or rack in a store. self-se·lected adj. self-se·lective adj.