noun
arrow wheel; decorative windmill on a carp streamer pole
A traditional ornament: a small windmill attached to the top of a 鯉のぼり (carp streamer) pole, often seen during Children's Day (May 5th).
See also: 鯉のぼり
鯉のぼりの竿の先に矢車が回っている。
An arrow wheel is spinning at the top of the carp streamer pole.
鯉のぼり refers to the carp streamers themselves, while 矢車 is the decorative windmill attached to the pole.
Compound of 矢 (arrow) and 車 (wheel), referring to the arrow-like spokes of the windmill.