long sword with bird-head pommel
Abbreviation of 鳥頭の太刀 (torigashira no tachi). Refers to a specific type of long sword with decorative bird-head carvings on the pommel. Rare, historical term.
See also: 鳥頭の太刀
鳥頭 is sometimes used as an abbreviation for 鳥頭の太刀 (a long sword with bird-head carvings).
Compound of 鳥 (tori, 'bird') and 頭 (kashira, 'head'), referring to the bird-shaped pommel decoration. The exact historical derivation is uncertain.