咽 has three readings. Fourth-tone yàn = to swallow: 吞咽, 咽下. First-tone yān = throat: 咽喉, 咽炎. Fourth-tone yè = to choke with sobs: 呜咽. One of the trickiest multi-reading characters.
Mouth radical on the left, the indexing radical and the body part involved. Swallowing happens at the back of the mouth where it narrows into the throat; the radical anchors 咽 in the eating family with 吃, 喝, 吞, 喉.
Right side 因 supplies the sound, yīn shifting to the three readings yàn / yān / yè. 因 originally pictured a person 大 inside a mat, suggesting 'enclosed by', a faint echo of food enclosed in the throat. Same phonetic seeds 姻 and 茵.
