Iḍā
Lunar channel (left)
Lunar nāḍī flanking suṣumṇā on the left. Pale, cooling, associated with the moon and the descending vital breath. Per Avalon's reading of the inverted ājñā triangle, iḍā curves to meet suṣumṇā at the brow centre, then terminates at the left nostril.
Point 2 of 3 in Three Principal Nāḍīs (suṣumṇā / iḍā / piṅgalā)
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Sat-Chakra-Nirūpaṇa v.1 (primary_canonical)
Sat-Cakra-Nirūpaṇa v.1 describes Iḍā as the left-flanking channel of the central Suṣumṇā and gives its lunar association; the brow convergence and nostril termination are part of the verse's nāḍī diagram in the standard Avalon recension.
Woodroffe, The Serpent Power p.108 (secondary)
“The Nāḍī Iḍā… moonlike in nature, courses on the left.”