juumonji_yari
A type of yari (Japanese spear) distinguishable by the two blades perpendicular to the central blade, forming a cross. The blades can be straight or curved upward (somewhat resembling a trident) or downward.
十文字 literally means "cross" or "letter ten" because it resembles the kanji 十 (10).
See also
- Katakama yari, similar, but with one (large) side blade
- Partisan (weapon)