Trishna (Vedic thought)
Trishna (Sanskrit: तृष्णा) means – 'thirst' ("Caitanya Caritamrta" Adi 4.149), 'aspiration' ("Caitanya Caritamrta" Antya 14.44), 'longing', 'craving' or 'lusty desires' ("Srimad Bhagavatam" 9.19.18), or as तृष्णज् meaning covetous, greedy or thirsting. "Trishna" is the Eighth "Nidana", spiritual love. Meaning. The Sanskrit root of the word "Tṛishṇā" (तृष्णा) is "Tṛish" (तृष्) meaning to be thirsty, to thirst, to thirst for (metaphorically), strong desire or long for. In the Vedas the accent is on the first syllable as in - "Tṛishyā" (to be thirsty), "Tṛishṇākshaya" (cessation of desire, tranquillity of mind, resignation, patience, content), "Tṛishnāghna" (quenching the thirst), "Tṛishṇāmaya" (ill with  thirst), "Tṛishṇāmāra" (dying of thirst), "Tṛishṇāri" (enemy of thirst), "Tṛishālu" (thirsting much, very thirsty), "Tṛishyat" (thirsting) or "Tṛishya" (thirst). "Trishna" in Pali ("tanha") means thirst for life. Vedic relevance. The word "Trishna" appears in the Rig Veda in a few mantras where it refers to greed, craving, hankering or longing, and the like. In mantra Rig Veda (I.XXXVII.6), Rishi Ghora Kanva states: He speaks about the (unfavourable ) wind (निर्ऋतिः) which flows on greedily (तृष्णया). And, in mantra Rig Veda (I.LXXXV.11), Rishi Rahugano Gotama stating - speaks about the wise ones craving (तृष्णजे) for opportunities to sate the thirst of those hankering  (तर्पयन्त ) for knowledge. Buddhist relevance. Gautama Buddha said that the cause of sorrow – the second of the Four Noble Truths – is desire; and the cause of desire is "tanha" or "trishna". Buddhism teaches the doctrine of inaction, i.e. cessation of activity, desiring or doing little. The extinction of craving of the desire for existence in all its forms and the consequent cessation of suffering is Nirvana (Nirvana is grasping nothingness and possessing nothing which state is reached through the knowledge of impermanence and voidness). Vivekananda holds that the Buddhist doctrine of giving up "trishna" ('greed') is an offshoot of Advaita  Vedanta. Puranic relevance. According to the "Puranas", "Trishna" is the daughter of Kamadeva or Kama, the god of love and husband of Rati; Aniruddha is her brother. Vishnu Purana tells us that "Anrita" ('falsehood') married his own sister, "Nikritti" ('immorality') and had two sons, "Bhaya" ('fear') and "Naraka" ('hell'), and two daughters, "Maya" ('illusion' or 'deceit') and "Vedana" ('torture') who again married each other. The son of "Bhaya" and "Maya" is "Mrityu" ('death'), and "Dukha" ('sorrow' or 'pain') is the son of "Naraka" and "Vedana". From "Mrityu" descended "Vyadhi" ('disease'), " Jara" ('decay'), "Shoka" ('sorrow' or 'grief'), "Trishna" ('desire' or 'greed ') and "Krodha" ('anger'). "Trishna" ('Greediness') is the wife or mistress of "Lobha" ('Greed'). Vedantic relevance. Shankara explains that the intellect ("buddhi") of those who perceive the Being as affected with difference of space etc., cannot be brought immediately to an intuition of the highest reality; Brahman is to be realized as attributeless. He states that even if the knowers of Brahman of themselves abstain from objects of sensual enjoyment yet the thirst ("trishna") caused by being addicted to sensuality in different births cannot at once be converted. Renunciation is "brahmacāryam" or "stri-vishaya-tyāga". "Trishna", that causes dukkha , the philosophical translation of which is unsatisfactoriness rather than pain, is immoderate desire as such; "Trishna" is the will-to-live. Upanishadic relevance. In the Brihadaranyaka Upanishad (IV.iv.6) in the passage – the word "Kāma" (काम) refers to desires – the man who desires migrates, but the man who is without desires never migrates; of him who is without desires, who is free from desires, the objects of whose desire have been attained, and to whom all objects of desire are but the Self – the organs do not depart, being Brahman, he is merged in Brahman. It is held that the main  fundamental Buddhist thought, Nirvana i.e. the removal of suffering by removal of "trishna", is an echo of the afore-cited Upanishadic doctrine of union with Brahman by the removal of "Kāma". The truth is - that deeds come from "upādāna" (clinging to existence), "upādāna" comes from "trishna" (craving), "trishna" comes from "vedana" (torture), the perception of pain and pleasure, the desire for rest; sensation (contact with objects) brings desire for life or the will to live. In the Bhagavad Gita (Sloka XIV.7), Krishna tells Arjuna: Here, the word "Rāga" refers to attachment, and "Trishna", refers to the craving for what is  unattained. Implication. From the Chandogya Upanishad (VIII.viii.5, VIII.ix.1,VIII.xii.1-3) we learn that the term "Asura" (आसुर) signifies the natural and impulsive ('demonical') actions of the senses which are promoted by the desire for an object of pleasure called "Asu" (असु), and that the term "Deva" (देव), which is derived from the verb "Div" (दिव) signifying 'illumination', stands for the functions of the senses illuminated by reason. Prajapati tells Indra that the body which is mortal because it is covered by death is the seat of the self which is immortal and bodiless; anything embodied is within the range of the  desirable and the non-desirable which two aspects cannot affect one who has become unembodied. The tranquil one having become established in his own nature after rising up from his body reaches the supreme Light and becomes Brahman. Vishnugupta (Chanakya) in his Chanakya Niti tells us that "anger is personification of "Yama", ('the demi-god of death'), thirst is like hellish river "Vaitarani", knowledge is like "Kamadhenu" ('the cow of plenty'), and contentment is like "Nandanavana" ('the garden of Indra')".