स्त्री पुंवच्च

And so also a feminine word, ending with a वृद्ध affix, when similarly spoken along with the same word but which ends with a युवन् affix, is only retained and it is treated like a masculine.
When a word denoting gotra and in the feminine gender is compounded with another word denoting a yuvan, the first is retained and the last is dropped; and the feminine noun so remaining is then treated like the masculine. This aphorism makes an addition to the previous sutra and is governed by all the conditions mentioned in that sutra. Thus गर्गी + गार्ग्यायणः = गार्ग्यौ. Here note that the resultant form is the same as in the former sutra, namely the masculine.

Similarly दाक्षी + दाक्षायणः = दाक्षी (masculine dual of दाक्षि).

Vart:- The word stri in the sutra means Vriddha stri, that is the eldest daughter of a grandson, or a further descendant considered as the female head of the family. The words 'tal lakshanas chedeva viseshah' of the previous sutra govern this sutra also, i.e. the distinction between the two words must be in their formative element and not in any thing else.