This root is found in many English words, including:
* Spiracle: An opening that allows air to enter a body, such as the breathing holes of insects.
* Inspire: To breathe in, or to fill with an idea or feeling.
* Expire: To breathe out, or to come to an end.
* Aspirate: To breathe in strongly, or to pronounce a sound with a breath.
* Conspire: To plan together secretly.
* Respiration: The process of breathing.
While the literal meaning of "spir" relates to breathing, it can also be used in a metaphorical sense to describe the action of something that spreads or expands, much like the act of breathing itself.