noun
water caltrop; water chestnut
Refers to the aquatic plant Trapa japonica and its edible nut. Often used in the context of traditional Japanese food or pond vegetation.
池に菱が浮かんでいる。
Water caltrops are floating on the pond.
菱の実は茹でて食べられる。
The nuts of the water caltrop can be boiled and eaten.
noun
A historical spiked weapon scattered on the ground to hinder cavalry or foot soldiers. Also known as 撒菱 (まきびし).
忍びの者は逃げるときに菱を撒いた。
The ninja scattered caltrops as they fled.
The kanji 菱 is used for its meaning 'water caltrop' and by extension for the diamond-shaped weapon. The reading ひし is native Japanese.