鉄兜[tetsukabuto] steel helmet
兜虫[kabutomushi] rhinoceros beetle (esp. the Japanese rhinoceros beetle, Trypoxylus dichotomus)
内兜[uchikabuto] inside of a helmet
兜蟹[kabutogani] horseshoe crab
鳥兜[torikabuto] aconite (esp. species Aconitum japonicum)

兜頭巾[kabutozukin] helmet-shaped hood
兜率天[tosotsuten] Tusita heaven
勝って兜の緒を締めよ[kattekabutonoowoshimeyo] don't let your guard down even after a victory
角兜[tsunokabuto] spiked helmet

ランブル鞭毛虫[ranburubenmouchuu] giardia (flagellate protozoan)
ランブル鞭毛虫症[ranburubenmouchuushou] giardiasis
いも虫[imomushi] hornworm (caterpillar of a hawk moth)
益虫[ekichuu] useful insect
円虫類[enchuurui] round worms

夏虫[natsumushi] summer insect
蛔虫[kaichuu] roundworm (Ascaris lumbricoides)
害虫[gaichuu] harmful insect
鈎虫[kouchuu] hookworm
寄生虫[kiseichuu] parasite