From Hrasvaroma came a son named Siradhvaja (also called Janaka). When Siradhvaja was plowing a field, from the front of his plow (sira) appeared a daughter named Sitadevi, who later became the wife of Lord Ramacandra. Thus he was known as Siradhvaja

Expressions researched:
"From Hrasvaroma came a son named Siradhvaja (also called Janaka). When Siradhvaja was plowing a field, from the front of his plow (sir) appeared a daughter named Sitadevi, who later became the wife of Lord Ramacandra. Thus he was known as Siradhvaja"

SB Canto 9

From Hrasvaromā came a son named Śīradhvaja (also called Janaka). When Śīradhvaja was plowing a field, from the front of his plow (śīra) appeared a daughter named Sītādevī, who later became the wife of Lord Rāmacandra. Thus he was known as Śīradhvaja.

SB 9.13.18, Translation:

From Hrasvaromā came a son named Śīradhvaja (also called Janaka). When Śīradhvaja was plowing a field, from the front of his plow (śīra) appeared a daughter named Sītādevī, who later became the wife of Lord Rāmacandra. Thus he was known as Śīradhvaja.