Si Collection, Upper Volume Radical: Water (shuǐ) Entry: 7 Page 605, Entry 15 Identical to the character pronounced wu. According to the Jade Chapters (Yupian), the form derived from the character pronounced yu is the ancient version, while the form derived from the character pronounced yu is the modern version. Ouyang Xiu stated that the two forms were originally the same character; however, modern texts and commentaries use the modern form, which is likely a common variant. Additionally, in the Collected Rhymes (Jiyun), it is pronounced yu (level tone), with a sound identical to the character pronounced yu. The meaning is deep. Some distinguish between the two forms as separate characters.