1. impossible or very difficult to open

Examples

• The jar was completely unopenable despite our best efforts.
• She struggled with the unopenable package for several minutes.
• The vault door appeared to be unopenable without the proper code.
• His laptop bag had an unopenable zipper that was stuck.
• The medicine bottle was designed to be unopenable by children.
• After years of rust, the old chest became unopenable.