Let's go with that, and ignore Creationist attempts to vague the term
As you are talking about cosmology. creationism is the belief in a creator of all things and the creation of the universe out of nothing. Atheists don't believe in a creator; traditionally, they believed that the universe has always existed. Theology, at least Catholic theology, regards creationism as a theological doctrine concerning the origin of the human soul. For instance. Dr. Ludwig Ott wrote this in 1952. repprting the opinion of the Bible Commission (1909) As the sacred writer had no intention of representing with scientific accuracy the intrinsic constitution of things, and the sequence of works of creation but only of communicating knowledge in a popular way suitable to the idiom and the -prescientific development of his day, the account is not to be regardede as if it were.....