期限
qíxiàn · HSK 4
limit
⏳ 期 = period/term + 限 = limit; together: time-period limit = deadline
期 carries the sense of a scheduled period or term (as in 学期 semester), and 限 means boundary or restriction. Combined, 期限 names the bounded period you're allowed — a deadline or fixed term.
期 — 其 (phonetic) + 月 (moon/time)
期 is a phono-semantic compound. The right side 月 (moon) signals meaning, since lunar cycles marked fixed time periods in ancient China. The left side 其 supplies the sound. Together it points to a set time, period, or appointed date — meanings still carried today in words like 期间 and 日期.
限 — mound radical 阝 + 艮 (phonetic)
限 combines the 阝 (mound/hill) radical on the left with 艮 on the right, which provides the sound. The mound element suggests a boundary or barrier formed by terrain, and the character came to mean 'limit' or 'boundary' — the edge one cannot cross.