調整
ちょうせい · chousei · JLPT N2 · noun
adjustment
🎛️ 調 = tune + 整 = arrange, so 調整 = tune and arrange until it fits: adjustment
調 covers tuning, as in music tone, and 整 means put in order or level. Together they mean bringing something into proper working order by fine tuning, which is regulation.
整 — 束 bundle + 攵 tap/strike + 正 correct/upright
A compound character combining 敕 (to arrange, with 束 'bundle' and 攵 'strike/action') over 正 ('upright, correct'). The image is of striking a bundle into proper alignment, giving the meaning 'to put in order, arrange neatly.' From this came senses of 'whole, complete, tidy.'