n. The act or power of conceiving in the mind, or of forming a concept; that which is conceived in the mind.n. In philosophy: The act of conceiving or of forming a concept, or the concept itself; a notion.n. Improperly, the faculty of reproductive imagination.n. Thought, notion, or idea, in a loose sense: as, you have no conception how clever he is.n. A fanciful thought; a conceit.n. The act of becoming pregnant; the beginning of pregnancy; the inception of the life of an embryo; hence, figuratively, beginning; origination.