ETYMOLOGY: the term ‘Vajra’ has the following meanings: lightning (not thunder), powerful light, weapon of the god Indra, diamond, precious jewel.
In the spiritual teaching known under the name Mahayana, Vajra is the emblem, the attribute of the highest spiritual power.
GENERAL GUIDELINES: Vajra is the name of a subtle nadi, which begins at the end of the masculine genital organ and therefore, Vajra is the esoteric denomination of the penis.
Some Hindu yogis call this asana SUPTA VAJRASANA, fact which confirms that this asana awakens the energy of virility.
In Sanskrit, VIRA means ‘warrior’, ‘hero’, and ‘man’ in the ‘virile’ sense of the term. Virility is understood here in a broader sense – that is it refers to the solar, masculine energies, and is not restricted to the sexual connotation.