渡る
わたる · wataru · JLPT N5 · verb-godan
to cross over
🌉 wataru: cross WATer — what are (wata-ru) you crossing? Water.
渡 has the water radical 氵 on the left plus 度 (degree, measure): measuring your way over water. The sound wata- echoes water, so wataru = to go across water, a bridge, or a road.
渡 — water radical 氵 + 度 (measure/cross)
渡 combines the water radical 氵 with 度, which provides the sound and suggests measuring or passing across. Originally it meant to cross a body of water, like fording a river or ferrying across. Over time it broadened to mean 'to pass through' any transition, including time or stages of life.