The word qi may be little, but boy is it energetic. In fact, qi stands for the energy in everything. (It's also a handy word to know in Scrabble.)
In Chinese philosophy, qi, also spelled chior ch’i, is the life force that every person and thing has. Chinese medicine and acupuncture both address the concept of qi; if you’re feeling a little under the weather, an unbalanced qi may be the culprit. Martial arts also uses the concept: if you’ve ever practiced tai chi, then you’re already familiar with qi, just with a different spelling.