空ろ
うつろ · utsuro · JLPT N1 · noun
space
🫙 Kanji 空 means empty; here it is read うつ (utsu), plus suffix ろ = utsuro, hollow or blank
The kanji 空 means empty, and this word reads it as うつ with ろ added. Same kanji as in 空っぽ (karappo, empty). Often used for a blank, vacant gaze: うつろな目.
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.'