General:
* Aspire: To have a strong desire or ambition to achieve something.
* Conspire: To plan secretly to do something illegal or harmful.
* Expire: To come to an end; to die.
* Inspire: To fill someone with the urge or ability to do or feel something, especially to create something.
* Perspire: To sweat.
* Respire: To breathe.
* Transpire: To happen; to become known.
Less common:
* Dispire: To discourage or dispirit.
* Inspirited: Filled with enthusiasm or courage.
* Respiration: The process of breathing.
* Spirituality: The quality of being concerned with the human spirit or soul as opposed to material or physical things.
Note: The "-spir-" root often relates to breathing, spirit, or breath. This connection can help you understand the meaning of many "-spir-" words.