Ādīnavānupassanā-ñāna: 'knowledge consisting in contemplation of danger', is one of the 8 kinds of insight vipassanā that form the 'purification of the knowledge and vision of the path-progress see: visuddhi VI. 4. It is further one of the 18 chief kinds of insight.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.