noun The fertilization of an ovum by a sperm to form a zygote.
noun The start of pregnancy.
noun The formation of a conceptus or an implanted embryo.
noun The power or faculty of apprehending of forming an idea in the mind; the power of recalling a past sensation or perception; the ability to form mental abstractions.
noun An image, idea, or notion formed in the mind; a concept, plan or design.