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

兎や角言う[toyakakuiu] to say all kinds of things
まっ四角[masshikaku] square
アフリカの角[afurikanotsuno] horn of Africa
一角[ikkaku] corner
一角の人物[hitokadonojinbutsu] somebody (important)

一角獣[ikkakujuu] unicorn
烏犀角[usaikaku] black rhinoceros horn
鋭角[eikaku] acute angle
外角[gaikaku] outside corner
町角[machikado] street corner