Today we will look at the form वैयाकरणकिराताद् m-Ab-s from सुभाषितरत्नभाण्डागारम्।

वैयाकरणकिरातादपशब्दमृगाः क्व यान्ति संत्रस्ताः ।
ज्योतिर्नटविटगायकभिषगाननगह्वराणि यदि न स्युः ॥

Translation – Terrified by the hunter in the form of a grammarian, where would the deer in the form of corrupted words go if there were no caves in the form of the mouths of astrologers, actors, paramours, singers and physicians.

Note: The gist of the verse is that astrologers, actors, etc., keep using corrupted words, in spite of the grammarians pointing them out.

The प्रातिपदिकम् ‘वैयाकरण’ used in the compound form वैयाकरणकिराताद् is derived as follows –
व्याकरणमधीते वेद वा = वैयाकरणः – a person who studies or knows grammar

(1) व्याकरण अम् + अण् । By 4-2-59 तदधीते तद्वेद – To denote a person who studies or knows that (subject matter), the तद्धित: affix ‘अण्’ may be optionally applied following a syntactically related पदम् in which the सन्धिः operations have been performed, provided the पदम् ends in the second case affix and has a base which denotes that (subject matter).

(2) व्याकरण अम् + अ । अनुबन्ध-लोपः by 1-3-3 हलन्त्यम्, 1-3-9 तस्य लोपः ।

‘व्याकरण अम् + अ’ gets the designation प्रातिपदिकम्‌ by 1-2-46 कृत्तद्धितसमासाश्च। This allows 2-4-71 सुपो धातुप्रातिपदिकयोः to apply in the next step.

(3) व्याकरण + अ । By 2-4-71 सुपो धातुप्रातिपदिकयोः – A सुँप् affix takes a लुक् elision when it is a part of a धातुः or a प्रातिपदिकम्।
Note: The affix ‘अण्’ is a णित् (has the letter ‘ण्’ as इत्). This allows 7-2-117 तद्धितेष्वचामादेः to come for application to perform the वृद्धिः substitution in place of the letter ’आ’, which is the first vowel of the अङ्गम् ‘व्याकरण’। Even though the vowel ‘आ’ is already a वृद्धिः letter, the सूत्रम् 7-2-117 तद्धितेष्वचामादेः still comes for application as per the न्यायः ‘पर्जन्यवल्लक्षणप्रवृत्तिः’ – Just as rain falls equally on land as well as sea, similarly a rule is applied whether or not there is a net effect.
Since the letter ‘य्’ (which has come in place of the letter ‘इ’ as per the सूत्रम् 6-1-77 इको यणचि) in the अङ्गम् ‘व्याकरण’ (= ‘वि + आ + करण’) is at the end of a पदम्, the सूत्रम् 7-3-3 stops 7-2-117 here. And simultaneously, the augment ‘ऐ’ attaches prior to the letter ‘य्’।

(4) वै याकरण + अ । By 7-3-3 न य्वाभ्यां पदान्ताभ्यां पूर्वौ तु ताभ्यामैच् – A vowel that follows the letter ‘य्’ / ‘व्’ situated at the end of a पदम् does not take the वृद्धिः substitution (which would have been prescribed by 7-2-117 तद्धितेष्वचामादेः, 7-2-118 किति च), instead the augment ऐच् (letter ‘ऐ’ or ‘औ’) attaches prior to such a letter (‘य्’ or ‘व्’)।
Note: As per the परिभाषा-सूत्रम् 1-3-10 यथासंख्यमनुदेशः समानाम् the augment ‘ऐ’ attaches prior to the letter ‘य्’ and the augment ‘औ’ attaches prior to the letter ‘व्’, as the case may be.

Note: The अङ्गम् ‘वैयाकरण’ gets the भ-सञ्ज्ञा by 1-4-18 यचि भम् which allows 6-4-148 यस्येति च to apply in the next step.

(5) वैयाकरण् + अ । By 6-4-148 यस्येति च – When the letter ‘ई’ or a ‘तद्धित’ affix follows, the (ending) इ-वर्ण: (letter ‘इ’ or ‘ई’) or the (ending) अवर्ण: (letter ‘अ’ or ‘आ’) of a अङ्गम् with the भ-सञ्ज्ञा takes elision (लोपः)।

= वैयाकरण ।

The compound ‘वैयाकरणकिरात’ is a कर्मधारयः compound which may be explained as a शाकपार्थिवादिसमासः as follows –
वैयाकरणरूपः किरातः = वैयाकरणकिरातः – a hunter in the form of a grammarian