• mṛgayām — hunting expedition
  From mṛga (deer, beast). Mṛgayā is the classical kṣatriya pastime. Śāstra permits it only under restrictions — here Kṛṣṇa kills medhyān paśūn, animals offerable in yajña, refusing the prohibited kinds. Bhagavān-conducted mṛgayā is itself a model of dharmic restraint.
• saindhavam — of the Sindh country
  From Sindhu — the Indus region, famed for its warhorses. Kṛṣṇa rides the best of breeds. Gauḍīyas: even the Lord's mount is described — every detail of līlā is significant, because nothing in līlā is incidental.
• medhyān — fit for sacrifice
  From medha (sacrifice). Only paśus that are medhya — qualified for the altar — are killed. The qualifier limits the hunt strictly: dharmic mṛgayā has yajña as its only valid telos, distinguishing it from cruelty.
• yadu-puṅgavaiḥ — by the most heroic Yadus
  Compound: Yadu + puṅgava (bull, leader). The bulls-of-Yadus accompany Him. Gauḍīyas read the Yadu retinue as Bhagavān's eternal sakhya-pariṣad in the Dvārakā key, paralleling the cowherd-friends of Vraja.

A king on a Sindh-bred warhorse, surrounded by his bravest companions, hunts only those animals fit for the altar. The hunt is not sport but yajña-procurement; the kṣatriya's mṛgayā is dharmic when its target is sacrificial.