One of the names of the Indian demi-goddess 'Chandi' who in Akali Nihang Singh Khalsa thinking represents the power of highest Immortal Being - 'Akal'.
Chandi in Akali Nihang is represented by the sword. Hence it is another Sikh name for tulwar, shamshir or kharag etc.
Also see 'Akal', 'Talwar' and 'Ashtbuja'.