noun, noun or participle which takes 'suru'
flying into; jumping into
Archaic noun and suru-verb meaning to fly or jump into something. Not used in modern Japanese; encountered only in historical texts.
古い軍記物語に「敵陣に飛入する」とある。
In old war tales, there is a phrase 'to fly into the enemy camp'.
Compound of 飛 (hi, 'flying') and 入 (nyū, 'entering'). The exact historical derivation is uncertain, but it follows a classical kanji compounding pattern.