セン, かわ, か, こ, さわ, さんぼんがわ
stream, river, river or 3-stroke river radical (no. 47)
JLPT5 G1 S3 F181
A depiction of a curving *river* boring its way through the earth in linking distant points. Compare 河. In characters such as 巡 and 邕, 川 appears in the form 巛.
[Full Kanji Etymology List]