空白
kòngbái · HSK 7
blank space
📄 空白 = 空 (empty) + 白 (white/blank) = a blank, empty space
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.'
白 — pictograph; resembles 日 (sun) with a stroke on top
白 is generally considered a pictograph, traditionally explained as depicting the sun rising with a ray of light above it, hence the meaning 'white' or 'bright.' Some scholars instead see it as a drawing of a thumbnail or an acorn. From 'bright' it extended to 'clear,' 'plain,' and 'to state plainly.'