A Siddham in Tamil means "one who is accomplished" and refers to perfected masters who, according to Hindu belief, have transcended the ahamkara (ego or I-maker), have subdued their minds to be subservient to their Awareness, and have transformed their bodies (composed mainly of dense Rajo-tama gunas) into a different kind of body dominated by sattva. This is usually accomplished only by persistent meditation.

According to Jain belief Siddha are liberated souls who have destroyed all the karma bondings. Siddha do not have any kind of body, they are soul at its purest form. They reside in Siddha-shila which is situated at the top of the Universe.

A siddha has also been defined to refer to one who has attained a siddhi. The siddhis as paranormal abilities are considered emergent abilities of an individual that is on the path to siddhahood, and do not define a siddha, who is established in the Pranav or Aum – the spiritual substrate of creation. The siddhi in its pure form means "the attainment of flawless identity with Reality (Brahman); perfection of Spirit."

In the Hindu philosophy of Kashmir Shaivism (Hindu tantra), siddha also refers to a Siddha Guru who can by way of Shaktipat initiate disciples into Yoga.

Read more about Siddha:  Siddha or Siddhar (Tamil Tradition ), Siddha in Jainism, Siddha-shila, Siddhashrama, Siddha Sampradaya

Other articles related to "siddha":

Siddhaṃ Alphabet - Siddhaṃ Fonts
... Siddhaṃ is still largely a hand written script ... of these are capable of reproducing all of the Siddhaṃ conjunct consonants ... Electronic Texts Association have created a Siddhaṃ font for their electronic version of the Taisho Tripiṭaka, though this does not contain all possible conjuncts ...
Siddhaṃ Alphabet
... Siddhaṃ (Sanskrit सिद्धं, "accomplished" or "perfected" སིད་དྷཾ། Chinese 悉曇文字 pinyin Xītán wénzi Japanese 梵字, bonji Middle Chinese (Baxter-Sagart) sit-dom ... There is some confusion over the spelling Siddhāṃ and Siddhaṃ are both common, though Siddhaṃ is correct ... The name arose from the practice of writing the word Siddhaṃ, or Siddhaṃ astu (may there be perfection) at the head of documents ...
Siddha, Gandaki
... Siddha, Gandaki is a town and Village Development Committee in Kaski District in the Gandaki Zone of northern-central Nepal ...
Avadhoot - Siddha Siddhanta Paddhati
... The Siddha Siddhanta Paddhati is a very early extant Hatha Yoga Sanskrit text attributed to Gorakshanath by the indigenous tradition, as Feuerstein (1991 p ... the earliest hatha yoga scriptures, the Siddha Siddhanta Paddhati, contains many verses that describe the avadhuta ...
Siddhaṃ Alphabet - History
... Buddhist texts which were taken to China along the Silk Road were written using a version of the Siddhaṃ script ... This led to the retention of the Siddhaṃ Script in East Asia ... The practice of writing using Siddhaṃ survived in East Asia where Tantric Buddhism persisted ...