似曾相识
sì céng xiāng shí · HSK 7
seemingly familiar
🔁 似曾相识 = seem (似) + once before (曾) + mutually (相) + recognize (识)
Literally seem-once-mutually-recognize: it seems you two have already met. The four characters stack into the feeling that a brand-new scene was somehow recognized before, which is exactly déjà vu.
曾 — top 八 + 田-like body + 日 (steamer pictograph)
曾 originally pictured a tiered bamboo steamer with rising vapor, the ancestor of 甑 'steamer pot.' It was borrowed phonetically for the grammatical meanings 'once, formerly' (zēng) and 'great-grand-' in kinship terms. Later 甑 was created with the 瓦 'tile/pottery' radical to keep the original cooking-vessel sense.
识 — speech radical 讠 + 只 zhī (phonetic)
识 is a semantic-phonetic compound. The speech radical 讠 (言) signals meaning related to words or knowing, while 只 hints at the sound. Originally written 識 with 戠, it meant 'to recognize' or 'know'; later it broadened to include knowledge and awareness.