used as a term of comparison
寍 is a rare kanji whose standalone meaning is unclear. The given gloss "used as a term of comparison" suggests it may have been used in classical contexts to indicate a comparative sense, but its precise conceptual center is uncertain.
The exact historical development of 寍 is uncertain. It visually contains 宀 (roof), 心 (heart), and 皿 (dish), but the original semantic and phonetic roles of these components are unclear.
Under a roof (宀), a heart (心) rests on a dish (皿), as if weighing feelings against a standard—a scene of comparison.
For ネイ, imagine a person named Nay who always compares everything: Nay -> ネイ, and under the roof, Nay's heart is on a dish, comparing.