unarticulated

To express certain emotions, especially mirth, delight, or derision, by a series of spontaneous, usually unarticulated sounds often accompanied by corresponding facial and bodily movements.

笑：为表达某种情感，尤指高兴、快乐或嘲笑而发的一阵自发的，通常是不清晰的声音，并常伴随着脸部和身体的运动。