Among the pairs of words used often by the Hindu scriptures, the pair ‘dharma-adharma’ is perhaps the most recurrent. Since the etymological definition of ‘dharma’ is ‘that which supports and sustains,’ all that attempts to destroy or oppose or reverse this process of supporting and sustaining comes within the purview of the word ‘adharma.’ If dharma is the straight path that leads to abhyu-daya (well-being and prosperity) and niśśreyasa (spiritual perfection), adharma is the crooked path that leads away from both. If dharma indicates actions and duties, ritualistic or otherwise, which are in conformity with the teachings of the śāstras (holy scriptures) and ācāryas (spiritual and religious leaders), and not antagonistic to sampradāya (customs and traditions), adharma stands for all errors of omission and commission.
In practice however, the word is more frequently used in the sense of unrighteous deeds and conduct resulting in sin. For instance, telling lies, stealing, cheating, adultery and committing such other forbidden acts and crimes are adharma. Dereliction of duties and not discharging the responsibilities one is entrusted with, are adharma. Performing such acts as are not prescribed for one—for e.g., a brāhmaṇa taking to arms or agriculture even though there is no urgency or emergency—is also considered adharma.
The personified adharma, in the mythological lore, is said to have hiṁsā (violence) as his wife, anṛta (falsehood) as his son, and nikṛti (deceit) as his daughter. Māyā (delusion), bhaya (fear), vedanā (torment), naraka (hell), duḥkha (sorrow) and mṛtyu (death) are the other offsprings coming in that lineage (vide Viṣṇupurāṇa 1.7). Though the details of such lists may vary, the purport is clear: adharma is at the root of all our fears, troubles and sufferings.
In Jaina metaphysics, adharma is considered to be a dravya (substance) responsible for restful state and immobility of things.