समानोदरे शयित ओ चोदात्तः

Operational rule vidhi

The affix यत् comes in the sense of 'who sleeps' after the word समानोदर in the Locative -7th case construction and the उदात्त falls on the letter ओ.

Word by word (padaccheda)

Right context समान- उदरे saptamī · ekavacanaSubstitute / term शयितः prathamā · ekavacanaWord ओ Indeclinable च avyayaSubstitute / term prathamā · ekavacana

Right context Saptamī (7th case): "when X follows", the operation applies to what precedes (1.1.66 तस्मिन्निति निर्दिष्टे पूर्वस्य). Also a condition or domain ("in the sense of").
Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
Word Case not marked in the source data.
Indeclinable An avyaya such as च "and", वा "optionally", न "not".

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

Full reading

समान-उदरे शयितः ओ च

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

Commentary

The affix यत् comes in the sense of 'who sleeps' after the word समानोदर in the Locative -7th case construction and the उदात्त falls on the letter ओ।
The word शयित is equal to स्थितः 'remain'. Thus समानोदरे शयितः = समानोदर्यः 'uterine brother' i. e. who has slept in the same womb. See 6.3.88.

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