Anusvara: the Indic nasal diacritic and its functions

Forms and general behavior

Different scripts represent the anusvara with different shapes. In Devanagari and related alphabets it usually appears as a dot above a letter (often called a bindu), for example मं which is commonly transliterated as maṃ or maṁ. In Bengali the mark appears as a small circle above a slanted line (ং) and is locally known as onushshar or onushshor. Many other Brahmic-derived scripts have comparable symbols. Technically the sign is often treated as a diacritic because it is written adjacent to the preceding consonant; however, in the phonology of some languages it behaves like an independent consonant.

Pronunciation and phonetic roles

The phonetic value of the anusvara varies. In several modern Indo-Aryan languages it signals a nasal that assimilates to the place of articulation of a following consonant (a homorganic nasal), so it may surface as [m], [n], [ɳ], [ŋ], etc., depending on context. In other environments it indicates nasalization of the vowel rather than a consonantal nasal. In Bengali, for example, the onushshar typically represents a velar nasal [ŋ] and has merged with the consonant ঙ (ungô) in the spoken language. In classical Sanskrit reading traditions the anusvara is sometimes treated as a distinct nasal phoneme or as a marker of nasalization depending on grammatical and metrical considerations. For more technical background on diacritic function see diacritic resources.

Script-specific notes and orthography

Orthographic treatment differs by script. In Devanagari the dot is placed above the consonant and is encoded as a separate combining sign in digital encodings; it often combines with other vowel marks in typographic layouts. In Bengali the onushshar is written as a compact glyph attached to the preceding consonant and is never pronounced with the inherent vowel; it cannot carry a vowel sign, so a different consonant letter is used if a nasal occurs before a vowel. Printed and bannered text in Bengali keeps the onushshar visually adjacent to the previous consonant even when other letters are separated: e.g., বাংলা is analyzed as ba+ŋ+la in pronunciation but the mark remains attached in the written word. Readers interested in Bengali sound patterns can consult sources on Bengali phonology.

History, encoding and transliteration

The use of a symbol to indicate nasality has deep roots in the Brahmi-derived writing systems and is attested in medieval and classical manuscripts. Over time the symbol evolved in shape and function in different regions. In modern practice transliteration conventions often render the anusvara as ṃ or ṁ (a Latin letter with a dot or underdot) when converting Indic words to Roman script. In digital text each major script provides a dedicated code point or combining mark for the anusvara, enabling consistent rendering and processing across platforms.

Importance and distinctions

Recognizing the anusvara is important for accurate pronunciation, linguistic description, and proper orthography in several South Asian languages. It should be distinguished from related marks: the candrabindu, which more explicitly signals vowel nasalization in some traditions, and individual nasal consonant letters, which represent full consonantal segments. The precise role of the anusvara—whether as consonant, vowel nasalizer, or assimilating marker—must be determined by the orthographic and phonological rules of each language rather than by a single universal definition.

• Common examples: Devanagari मं (maṃ), Bengali বাংলা (baŋla).
• Functions: nasal consonant, nasalization marker, assimilating homorganic nasal.
• Related signs: candrabindu, independent nasal letters.