The affix khaś comes after the verbs dhmā 'to blow' and dhe 'to suck' when nāsikā 'nose' and stana 'breast' are in composition with them as object.,
The rule of yathasankhya as given in 1.3.10 does not however, apply here. For स्तन is compounded with धेट्; as (स्तन + धे + खश् = स्तन + मुम् + धे + शप् + खश् = स्तन + म् + धय् + अ + अ) = स्तनन्धयः 'an infant' (sucking the breast).
But नासिका is compounded with both ध्मा and धे; as नासिका + ध्मा + खश् = नासिक + म् + धम + अ 6.3.66 and (67); 7.3.78 = नासिकन्धमः 'blowing and breathing through the nose'. So also नासिकन्धयः 'drinking through the nose'.
That the rule of yathasankhya does not apply here, is indicated by the irregular construction of the Dvandva compound नासिकास्तनयोः. By rule (II. 2. 84.) the word स्तन containing fewer syllables ought to have stood first; one irregularity lets in another.
The feminine of स्तनन्धयः is स्तनन्धयी, as the verb धे has an indicatory ट् ।,