• kārṣṇiḥ — the son of Kṛṣṇa
  Patronymic from Kṛṣṇa. The Bhāgavatam uses this title repeatedly in this chapter (v.11, 21, 23) to keep reminding the hearer: every act of valor that follows belongs to Kṛṣṇa's potency expressed through His son.
• rūḍha-yauvanaḥ — having attained full youth
  Compound: rūḍha (fully grown, established) + yauvanaḥ (the state of youth). The same rūḍha appears at v.40 (rūḍha-bhāvāḥ — full-blown ecstasy). The poet links Pradyumna's bodily maturation to the bhāva He will provoke.
• nārīṇām — the enchantment of women
  Genitive plural nārīṇām (of women) + vibhramam (bewilderment, agitation). Same family as bhrama (whirl). The reader is told now what v.27-28 will dramatize: Pradyumna's beauty, like Kṛṣṇa's, is intrinsically captivating — not a moral failing of the women who see Him.
• vīkṣantīnām — of those (women) who looked upon Him
  Present participle, genitive plural. The act of looking (vīkṣaṇa, darśana) is the medium of attraction. Gauḍīya bhakti is darśana-based: the body of the Lord (or His aṁśa) is itself enchanting, not as a temptation to be feared but as a fact of His svarūpa.

• Padaseva Pr SB 10-55-09 Russian Translation
  His Grace Padaseva Prabhu· Russian
• Padaseva Pr SB 10-55-09 Oriya
  His Grace Padaseva Prabhu· Oriya
• Bhanu Sw SB 10-55-09-40 - Krishna his shaktis Jiva%27s free will all together makes the pastime attractive - ISKCON Chennai
  His Holiness Bhanu Swami· English
• JAS SB-10-55-09-10 - Leading Marriage Life Knowing Well Its Purpose - 2015-01-11 ISKCON Chowpatty
  His Holiness Jayadvaita Swami· 2015-01-11· English

• What in your spiritual life is maturing faster than your worldly timeline expects?
• Where do you under-honor swift development because it doesn't match human pace?

In a short span Pradyumna grows to full youth — sun rising from horizon to zenith in what felt like a single morning. The Lord's expansions are not bound by ordinary developmental clocks; the form arrives when the līlā needs it.