世代
shìdài · HSK 7
generation
⏳ 世代 = 世 (world/age) + 代 (generation) — two era-words stacked into one epoch
世 means world or age and 代 means a generation or to replace one with the next. Put together they name a whole period or epoch — one age handing off to the following one. Pronounced shìdài, falling-falling.
代 — person radical 亻 + 弋 (stake/dart, phonetic)
代 is a semantic-phonetic compound: 亻 (person) gives the meaning and 弋 supplies the sound. The original sense was one person taking the place of another, which broadened to 'substitute,' 'replace,' and then 'generation' or 'era' — successive groups of people replacing the previous.