From Japanese-English FreeDict Dictionary ver. 0.1:
[ichi1] 空 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, (word containing out-dated kanji) 虚 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, [ichi1] そら /sˈo̞ɽä/
1. (noun (common) (futsuumeishi))
sky, the air, the heavens
2. weather
3. far-off place, distant place
4. (often as 〜空もない)
state of mind, feeling
5. (usu. as 空で)
(from) memory, (by) heart
6. falsehood, lie
7. (noun, used as a prefix)
(before an adjective)
somehow, vaguely
8. (before a noun or a verb)
fake
From Japanese-English FreeDict Dictionary ver. 0.1:
虚 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 空 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 洞 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, うろ /ˈɯᵝɽo̞/, (out-dated or obsolete kana usage) うつお /ɯᵝtsˈɯᵝo̞/, (out-dated or obsolete kana usage) うつほ /ɯᵝtsˈɯᵝho̞/, (虚) (空) (out-dated or obsolete kana usage) うつせ /ɯᵝtsˈɯᵝse̞/
(noun (common) (futsuumeishi))
hollow, cavity, hole
From Japanese-English FreeDict Dictionary ver. 0.1:
虚 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, きょ /kʲˈo̞/
1. (noun (common) (futsuumeishi))
unpreparedness
2. falsehood
3. 二十八宿, 玄武・げんぶ・2 [astronomy, etc. term] Chinese "Emptiness" constellation (one of the 28 mansions)