空调
kōngtiáo · HSK 3
air conditioner
❄️ 空调 = empty/air (空) + adjust/regulate (调)
空 means air or empty; 调 means to adjust or tune. Together: the device that adjusts the air. The same 调 shows up in 调节 (to regulate) and 空气 (air) shares 空.
空 — cave radical 穴 + 工 (phonetic)
Originally a phono-semantic compound: 穴 (cave, hole) gives the meaning of emptiness or hollow space, while 工 supplies the sound. The earliest sense was 'hole' or 'cavity,' which extended to 'empty,' 'sky,' and 'in vain.' The reading kòng (4th tone) specifically means 'free time' or 'vacancy.'
调 — speech radical 讠(言) + 周 zhōu (phonetic)
调 is a semantic-phonetic compound. The 讠(言) radical signals 'speech' or 'words,' while 周 supplies the sound. Originally meaning to harmonize or coordinate through words, it later extended to 'tune,' 'adjust,' and 'melody' (read diào), and 'mix evenly' or 'mediate' (read tiáo).