ठ-अज्-आदाव् ऊर्ध्वं द्वितीयाद् अचः

Karika

चतुर्थादनजादौ च लोपः पूर्वपदस्य च ।
अप्रत्यये तथैवेष्ट उवर्णाल्ल इलस्य च ॥

The word लोप is understood here from the last sutra The word ऊर्द्ध्वम् indicates that the whole of that portion of the term which follows the second vowel should be elided, otherwise, only the first letter of the third syllable would have been elided by (1. 1. 54). The illustrations have been given above. Thus देवदत्त + इक; here all the letters after the अ of देव should be elided : as देविकः, so also देवियः, देविलः ॥

The affix ठ is replaced by इक् or क 7.3.50 and 7.3.51 hence its special mention in this sutra. For had it not been used, the sutra would have run thus. 'When an affix beginning with a vowel follows &c'. This rule would have applied to इक substitute of ठ, but not to क substitute of ठ which comes after words ending in उ, ऋ, त्, इस् and उस् ॥ But it is intended that क (and not इक) substitute of ठ should be added to words whose second syllables end in उक् (उ or ऋ) vowels. If it be said that इक substitute of ठ would be sufficient for words like वायुदत्त &c. also as it will cause the elision of the third and subsequent syllables; and when such syllables are elided, क would be the proper substitute to add to वायु and not इक, which we can do by the rule of sthanivat; we say, it is not so. For if it were the case, we should add the क substitute and not इक in the following: मथित + ठक् 6.4.51= मथित् + ठक् 6.4.148, because, after elision, मथित् ends with त् ॥ But we know that क is not added but इक, and we have मथितिकः ॥ Hence the emplyment if ठ in the sutra is proper as वायुदत्तः—वायुकः, पितृदत्तः-पितृकः ॥

Vart:- It should be stated that the portion after the fourth vowel is elided in certain cases. As अनुकम्पितो बृहस्पतिदत्तः-बृहस्पतिकः, बृहस्पतियः, बृहस्पतिलः ॥

Vart:- When an affix not beginning with a vowel follows, the elision is optional. Thus देवदत्त + कन् = देवदत्तकः or देवकः, यज्ञदत्तकः or यज्ञकः ॥

Vart:- There is elision of the first term, when these affixes ठच् &c denoting compassion, whether beginning with vowel or not, follow. Thus दत्तिकः, दत्तिलः, दत्तियः, दत्तकः from देवदत्त or यज्ञदत्त or वायुदत्त &c.

Vart:- The dimunitive of compassion or endearment may be formed without adding any affix, by simply dropping either the first or the second term of the name. Thus दत्तः or देव from देवदत्तः, सत्यभामा—भामा & सत्या ॥

Vart:- The affix इल is replaced by ल after a word ending in उ as, भानुलः from भानुदत्तः, वसुलः—वसुदत्तः ॥ So also after a word ending in ऋ as सवितृलः ॥

Vart:- When the second vowel is ओ, औ, ए or ऐ, then this is also elided. As लहिकः from लहोडः, कहिकः from कहोडः ॥

Vart:- When the first member consists of a single syllable, there is elision of the second member : as वाचिकः from वागीशाः (the ग् changed back to च् because the stem is now भ and not पद, and rule 8.2.39 does not apply.) So also; स्रुचिकः, त्वचिकः ॥ The form षडिकः (and not षषिकः from षष्) is an exception. It is dimunitive of षडङ्गुलिदत्तः ॥,