来信
lái xìn · HSK 5
incoming letter
📨 来 = come + 信 = letter/message; a letter that comes to you
来 means 'come' and 信 means 'letter' or 'message', so 来信 literally reads as an incoming letter. By extension it also works as a verb meaning to send a letter to this address.
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).
信 — person 亻 + speech 言
信 combines 亻(person) with 言(speech), depicting a person standing by their words. The original sense is 'truthfulness' or 'sincerity'—what a person says can be trusted. From this it extended to 'believe,' 'trust,' and later 'message' or 'letter,' since a letter carries one's word.