In Indian mythology, the word chakra refers in particular to the discus, a weapon used by some of the gods, and by Vishnu in particular. Vishnu's chakra is called the Sudarshana Chakra; you can read more about that at Wikipedia. Here Vishnu holds the Chakra in his upper right hand:
There is also a sports term in English that comes from Sanskrit chakra. The English word "chukker" ( also spelled "chukka" and "chucker") refers to a period in a polo game. It comes from Hindi chakkar, which comes in turn from Sanskrit chakra. The phrase "chukker boot" refers to a type of leather boot worn by polo players.
The image below shows the chakras as depicted in a yoga manual from the 17th century: