Antonyms for the term "being contained in" include "escaping from," "outgrowing," and "surpassing." If something is "escaping from" a container or a space, it means it is no longer contained and has become free. "Outgrowing" refers to a situation where something or someone becomes too big or too advanced for a certain container or space. "Surpassing" refers to an object or concept that exceeds the boundaries of a limited space, exceeding expectations or limits. All three antonyms suggest a freeing of limitations, whether it's physically or in terms of growth and progress.