dhatu

Dhatu is a Sanskrit term used in multiple Indian traditions to denote two distinct concepts: a verbal root in Sanskrit grammar and a bodily tissue in Ayurveda. Despite sharing the same word, the technical meanings arise in different theoretical frameworks and are not interchangeable.

In Sanskrit grammar, a dhatu is the verbal root or base from which word forms are derived. It represents the core sense of a verb and remains constant while affixes, prefixes, and inflectional endings attach to produce finite verbs, participles, and nominal derivatives. Grammarians distinguish dhatus from the actual conjugated form; the dhatu supplies the stem for systematic derivation. The treatment of dhatus underpins many morphological rules, including the formation of causatives, desideratives, and other verbal operations, and various schools classify dhatus into groups based on phonology and semantics.

In Ayurveda, dhatu refers to one of seven bodily tissues that compose and sustain the body: rasa, rakta, mamsa, meda, asthi, majja, and shukra. Each dhatu arises from digestion and transformation of food and is nourished in a sequential order by the preceding dhatu and by the digestive fire (agni). Proper nourishment and balance of the dhatus are considered essential for health, while imbalances or accumulation can contribute to disease. Some texts also discuss additional or eighth dhatus, such as ojas, in extending the system.

The term also appears in other scholarly contexts as a general notion of a “basis” or “element” within a knowledge system, reflecting its broader sense as a foundational component.