お七夜[oshichiya] name-giving ceremony
七つ[nanatsu] seven
七つの海[nanatsunoumi] the seven seas
七屋[nanatsuya] pawnshop
七回忌[shichikaiki] seventh anniversary of a death

七角形[shichikakkei] heptagon
七曲がり[nanamagari] tortuous or spiral (path)
七月[shichigatsu] July
七賢[shichiken] the Seven Wise Men (of Confucius's Analects)

一か八か[ichikabachika] sink or swim
嘘っ八[usoppachi] downright lie
嘘っ八百[usoppappyaku] full of lies
嘘八百[usohappyaku] full of lies
八釜しい[kamabisushii] noisy

口八丁[kuchihacchou] voluble
三十八度線[sanjuuhachidosen] the Thirty-eighth Parallel
四苦八苦[shikuhakku] being in dire distress
四通八達[shitsuuhattatsu] traffic network extending in all directions
四方八方[shihouhappou] in all directions

ご苦労様[gokurousama] thank you very much for your ...
御苦労さん[gokurousan] I appreciate your efforts
苦力[kuurii] coolie
悪戦苦闘[akusenkutou] hard fighting
気苦労[kigurou] worry

夜露死苦[yoroshiku] well
狭苦しい[semakurushii] cramped
勤苦[kinku] toil and hardship
苦い[nigai] bitter
苦しい[kurushii] painful

し難い[shinikui] hard to do
一難[ichinan] one difficulty
火難[kanan] fire calamity
海難[kainan] shipwreck
患難[kannan] affliction

危難[kinan] peril
及び難い[oyobigatai] hard to attain to
救難[kyuunan] rescue
救難ヘリコプター[kyuunanherikoputaa] rescue helicopter
苦難[kunan] suffering