visargan.

1819 H. H. Wilson et al. Dict. Sanscrit & Eng. p. xlii A final Viserga or its omission, and a final nasal mark or its omission, are always optional.

1886 Encycl. Brit. XXI. 270/1 The Sanskrit alphabet consists of the following sounds…visarga (ḥ) a hard aspirate, standing mostly for original s or r.

1939 Year's Work Eng. Stud. 1937 29 It is a pity that Flasdieck consistently uses the visarga (transliterated as ḥ) for the final letter of Sanskrit words originally ending in s; for only the reader familiar with Sanskrit and its rules of sandhi will at once realize that the first person plural of the substantive verb given as Sanskrit smaḥ..is to be taken for etymological purposes as equivalent to smas.

1953 W. S. Allen Phonetics in Anc. India ii. 50 Since these variants [sc. -ḥ, -x, and -ø] are not included in the alphabet, special names are devised for them [by the old Indian phoneticians], viz. visarjanīya (or later visarga) for -ḥ, etc... We shall perhaps be giving the most direct and phonetically appropriate translation if we render it by ‘off-glide’, as referring to the breathy transition from the vowel to silence.

1975 Language 51 120 The first of these rules obligatorily assimilates a dental stop or continuant before any following coronal (dental, palatal, or retroflex) stop... The third converts s to visarga before word boundary.