त्रिस् /tris/ adv. трижды

Monier-Williams Sanskrit-English Dictionary
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 त्रिस् [ tris ] [ trí s ] ind. ( Lit. Pāṇ. 5-4 , 18) thrice , 3 times Lit. RV. ( [ saptá ] , 3 x 7 , Lit. i , iv , vii ff. ; [ áhnas ] or [ áhan ] , " thrice a day " , Lit. i , iii f. , ix f. ; cf. Lit. Pāṇ. 2-3 , 64) Lit. ŚBr. Lit. KātyŚr. Lit. Mn. ( [ abdasya ] , " thrice a year " , Lit. iii , xi)

  before gutturals and palatals ( ( cf. Lit. RV. viii , 91 , 7 ) ) [ ḥ ] may be substituted by [ ṣ ] Lit. Pāṇ. 8-3 , 43.

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