Apparently a primary word; a stone (literally or figuratively) -- (mill-, stumbling-)stone.

λίθοι (lithoi) − 4 Occurrences

λίθοις (lithois) − 3 Occurrences

λίθον (lithon) − 26 Occurrences

λίθος (lithos) − 9 Occurrences

λίθου (lithou) − 2 Occurrences

λίθους (lithous) − 3 Occurrences

λίθῳ (lithō) − 10 Occurrences

λίθων (lithōn) − 2 Occurrences