Definition: a letter of the alphabet, such as a (अ) or i (इ) or h (ह) or y (य्) or the like. The word was originally applied in the Prātiśākhya works to vowels (long, short as also protracted), to consonants and the ayogavāha letters which were tied down to them as their appendages. Hence अक्षर came later on to mean a syllable i. e. a vowel with a consonant or consonants preceding or following it, or without any consonant at all. cf. ओजा ह्रस्वाः सप्तमान्ताः स्वराणामन्ये दीर्घा उभये अक्षराणि R Pr. I 17-19 cf.एकाक्षरा, द्व्यक्षरा etc. The term akṣara was also applied to any letter (वर्ण), be it a vowel or a consonant, cf, the terms एकाक्षर, सन्ध्यक्षर, समानाक्षर used by Patañjali as also by the earlier writers. For the etymology of the term see Mahābhāṣya अक्षरं न क्षरं विद्यात्, अश्नोतेर्वा सरोक्षरम् । वर्णे वाहुः पूर्वसूत्रे । M. Bh. Āhnika 2 end.