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)

一弦琴[ichigenkin] single-stringed Japanese zither
琴線[kinsen] heartstrings
三角琴[sankakugoto] trigon (a musical instrument)
手風琴[tefuukin] accordion
心の琴線[kokoronokinsen] heartstrings

たて琴[tategoto] harp
風琴[fuukin] organ
木琴[mokkin] xylophone
提琴[teikin] tiqin (2 or 4-stringed Chinese instrument played with a bow)

一絃琴[ichigenkin] single-stringed Japanese zither
管絃楽[kangengaku] orchestral music
絃楽[gengaku] music for strings
絃楽器[gengakki] stringed instruments
絃声[gensei] sound of the strings

絃線[gensen] catgut
五絃[gogen] five strings
三絃[sangen] three-stringed instrument
絃歌[genka] singing and (string) music