कासूगोणीभ्यां ष्टरच्

Operational rule vidhi

The affix ष्टरच् (तर with feminine -- अन्यतो ङीष् (4.1.40)) comes in expressing diminution after the words 1. कासू and 2. गोणी.

Word by word (padaccheda)

Left context कासू- गोणीभ्याम् pañcamī · dvivacanaSubstitute / term टर prathamā · ekavacana

Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.

Dotted words are technical terms. Hover or tap one to see its card.

Pink letters are it-markers (anubandhas), tags dropped by 1.3.9. Hover or tap one for the rule that marks it, or try the it-letter finder.

Full reading

कासू-गोणीभ्याम् ष्टरच्

Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.

Commentary

The affix ष्टरच् (तर with feminine -- अन्यतो ङीष् 4.1.40) comes in expressing diminution after the words 1. कासू and 2. गोणी।
Thus हृस्वा कासूः = कासूतरी 'a small lance'; गोणीतरी 'a small sack'.

Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.