"Dedecoration" is a relatively uncommon term, but there are several synonyms that convey similar meanings. "Undecoration" refers to the act of removing decorations, while "stripping" implies the removal of something (in this case, decorations) from a surface or area. "De-accessorizing" is a more specific synonym that applies to the removal of decorative objects from a space. "De-dressing" or "un-dressing" could be used to describe the removal of ornamental clothing or accessories. "Unadornment" is a more formal synonym that suggests the removal of unnecessary embellishments, while "bareness" conveys a sense of emptiness or simplicity.