平たい
ひらたい · hiratai · JLPT N1 · i-adj
flat
🛹 平 (flat) + 坦 (smooth, open): like a flat 'hira' plain you can 'tai' (lie down) on
平 — horizontal stroke 一 + 干 with two dots 八
平 originally depicted a balance or scale being level, suggesting evenness. The horizontal lines and symmetrical dots evoke a flat, balanced surface. Over time it extended from 'level/flat' to broader senses like 'calm,' 'peaceful,' and 'ordinary.'