fundamentally russian

• суще́ственно

  significantly, substantially, considerably, greatly, much, dramatically, essentially, materially, drastically, fundamentally

• кардина́льно

  dramatically, fundamentally, radically, cardinally

Examples

• Сама́ постано́вка вопро́са в ко́рне неверна́.The question itself is fundamentally wrong.
• Э́то в ко́рне несправедливо.This is fundamentally unfair.