宛がう[ategau] to allot
宛てる[ateru] to address
宛ら[sanagara] just like
宛も[adakamo] as if
私宛[watashiate] my address

宛て[ate] aim
宛字[ateji] kanji used as a phonetic symbol, instead of for the meaning
一つ宛[hitotsuzutsu] one by one
宛て先[atesaki] address
宛て名[atena] (addressee's) name

空洞[kuudou] cave
空洞化[kuudouka] making hollow
鐘乳洞[shounyuudou] limestone cave (cavern, grotto)
洞窟[doukutsu] cave
洞穴[douketsu] cave

洞察[dousatsu] discernment
風洞[fuudou] wind tunnel
空洞化現象[kuudoukagenshou] (economic) hollowing-out phenomenon
洞見[douken] insight

洞簫[doushou] dongxiao (Chinese bamboo flute similar to a shakuhachi)
排簫[haishou] paixiao (ancient Chinese bamboo panpipes)

簫の笛[shounofue] xiao (vertical Chinese bamboo flute)