groan, chant, recite

吟 is composed of 口 (mouth) and 今 (now). 今 originally meant closing the mouth or holding something in the mouth (neither spitting out nor swallowing), conveying the idea of keeping speech or sound held in the mouth, thus producing a low, subdued sound from the mouth. Later, as 今 came to derive other meanings, 口 was added to create 吟, restoring and specifying this sense of uttering a low, murmuring sound. Therefore, 吟 refers to the sound emitted in pain or distress, or to chant, recite, or intone (as in poetry or verse).