Vajra Mushti
Vajra-mushti is a Sanskrit bahuvrihi compound translating to "one who is grasping a thunderbolt" or "one whose clenched fist is like a diamond". It is a name of Indra mentioned in the Ramayana epic.
In Tantric Buddhism Vajramusti is the name of a specific mudra (hand gesture). In Shingon Buddhism, it is also the name of a specific Bodhisattva mentioned in the Vajrasekhara Sutra.
In the Malla Purana, it is synonym of Bhukhandi, a cestus or knuckleduster-like weapon used by a class of wrestlers known as Jyeṣṭīmallas.
Terence Dukes in The Boddhisattva Warriors (2000) claims that vajramuṣṭi was also a term for an ancient Indian martial art of the kshatriya caste that was transferred to China along with the silk road transmission of Buddhism during the early centuries CE, contributing to the origins of Chinese martial arts. Dukes speculates that there was a martial art specific to early Buddhism which he terms "Bodhisattva Vajramukti". Dukes builds his theory on he term vajramuṣṭi itself, which he translates as "Thunder Fist". He claims that "Bodhisattva Vajramukti" was passed on within early Chinese Buddhist temples, as chuan fa, whence Japanese kenpō.