来回
láihuí · HSK 7
go to a place and come back
🔁 来回 = come (来) + return (回) = there and back, a round trip
Two motion verbs stuck together: 来 lái means come toward, 回 huí means go back. Chain them and you get the round-trip sense of going somewhere and coming back, or moving to and fro.
来 — pictograph of a wheat plant with grain heads
来 originally depicted a stalk of wheat with drooping grain heads, and meant 'wheat' in oracle bone script. It was later borrowed phonetically to write the unrelated verb 'to come,' which became its dominant meaning. The original 'wheat' sense was taken over by 麥 (now 麦).
回 — enclosure 囗 + smaller 囗 inside
回 is a pictograph of a swirling whirlpool or coiled spiral, shown as nested squares in modern form. The original meaning was 'to revolve' or 'turn around,' which extended to 'return' and 'a time/occurrence.' It also appears as a phonetic in characters like 茴 and 廻.