Vajradhara (Sanskrit, wielder of the thunderbolt).

1. One of the Five Jinas, he is identified with the Absolute or primordial reality (dharma-kāya). In iconography he is portrayed holding a thunderbolt (vajra) in his right hand symbolizing the power of compassion (karuṇā) and skilful means (upāya-kauśalya), and a bell (ghaṇṭā) in his left symbolizing the pure clear sound of transcendental insight (prajñā) which penetrates everywhere without obstruction. Dark blue in colour, he is anomalously depicted in the regal attire of a saṃbhoga-kāya Buddha.

2. A tantric term for a fully accomplished adept (siddha).

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)

○dhara mfn. holding a thunderbolt

• m. N. of Indra MBh. Kāv. &c

• of a Bodhi-sattva ( = vajra-pāṇi) MWB. 195 ; 201

• of a king Rājat

• -prabhāva m. having the power of Indra, Ragh

Sanskrit-English Dictionary, by M. Monier William