兜

helmet (of a warrior); headpiece

to accept one's inferiority; to take one's hat off to someone

to give up; to surrender; to strike one's colors

tokin; small black headgear worn by yamabushi

Kabutochō (neighbourhood of Nihonbashi, Tokyo, where the Tokyo Stock Exchange is located)

Colloquial

Tokyo Stock Exchange

horseshoe crab

Buddhism

Tusita heaven (one of the six heavens of the desire realm); Tushita

Abbreviation; Buddhism

Tusita (heaven, pure land)

helmet-shaped hood

Slang

frot (sex act)

Word usually written using kana alone

large-headed midnight fish (Poromitra crassiceps)

armored fish; armoured fish

tadpole shrimp (Triopsidae spp.); shield shrimp

rhinoceros beetle (esp. the Japanese rhinoceros beetle, Trypoxylus dichotomus)

steel helmet

Hercules beetle (Dynastes hercules)

Word usually written using kana alone

aconite (esp. species Aconitum japonicum); wolfsbane; monkshood

traditional bugaku hat

Proverb

do not let your guard down after a victory; tighten the strings of your helmet after winning

spiked helmet

Food, cooking

broiled fish head (esp. sea bream)

inside of a helmet; hidden circumstances

Pandanus boninensis (species of screw pine)

Food, cooking

simmered fish head (oft. sea bream)

Historical term

zunari helmet (made from 3-5 pieces of metal)