之繞

しん (shin) + 繞(にょう) (nyō, “kanji component that occupies the left and bottom”).

The meaning of しん (shin) is debated. Theories include:

1. 之 is an ateji (当(あ)て字(じ)); the 15th-century 壒(あい)嚢(のう)鈔(しょう) (Ainōshō) says that it is derived from 四(し)繞(にょう) (shinyō, literally “four-nyō”) since 辶 is written with 4 strokes.^[1]
2. 江(え)守(もり)賢(けん)治(じ) (Kenji Emori) suggests that it is from 進(しん) (shin), i.e. "the nyō of 進".^[1]
3. Euphonic sound change (音(おん)便(びん) (onbin)) from 之(し) (shi) to 之(しん) (shin),^[2] perhaps comparing the shape of the character 之 to the shape of the radical 辶.

• (Tokyo) しんにょー [shìńnyóó] (Heiban – [0])
• IPA^(key): [ɕĩɲ̟ːo̞ː]

之(しん)繞(にょう) • (shinnyō) 

1. the kanji component 辶 (a form of the radical 辵)

Sound shift from 之(しん)繞(にょう) (shinnyō) above.

• (Tokyo) しんにゅう [shìńnyúú] (Heiban – [0])^[3]
• IPA^(key): [ɕĩɲ̟ːɨː]

之(しん)繞(にゅう) • (shinnyū) 

1. synonym of 之繞 (shinnyō, “the kanji component 辶 (a form of the radical 辵)”) above