From Japanese-English FreeDict Dictionary ver. 0.1:
侘び /bˈi/, (irregular okurigana usage) 侘 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, (word containing irregular kanji usage) 佗 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, (word containing irregular kanji usage) 佗び /bˈi/, わび /wˈäbi/
(noun (common) (futsuumeishi))
the beauty to be found in poverty and simplicity, subdued taste, quiet refinement, sober refinement, wabi