मरणंवापि even if it meant death, शत्रूणाम् enemy, पराजयंवापि even defeated, निश्चित्य determined, वीराः heroes, इति thus, मतिम् thinking, कृत्वा to do, संयुगार्थिनः for the combat, निर्जग्मुः started.

Those heroes determined to defeat the enemy even if it meant death and went thinking for the combat.