期末
きまつ · kimatsu · JLPT N1 · noun
(end of the season or term)
🏁 期 = period/term + 末 = end, so 期末 = end of the term
末 means end or tail, as in 週末 (end of the week) and 年末 (year-end). Pair 期 (term) with 末 to get end of 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.
末 — tree 木 with extended top stroke marking the tip
末 is an indicative character: it shows the tree 木 with an emphasized horizontal line near the top to point at the treetop, the 'tip' or 'end' of the branches. From this concrete sense it extended to mean 'end,' 'final,' or 'minor/trivial' (as opposed to the root 本).