noun
approximant
A speech sound produced with a narrowing of the vocal tract, but not enough to cause turbulence. In Japanese phonetics, /j/ and /w/ are typical approximants.
日本語の「や」の子音は接近音に分類される。
The consonant in Japanese 'ya' is classified as an approximant.
Compound of 接近 (sekkin, 'approach') and 音 (on, 'sound'), a calque of the English linguistic term 'approximant'.