vortex filament; vortex line
Technical term in fluid dynamics and physics for a line-like vortex structure.
超流動体中では、渦糸が量子化された循環を持つ。
In superfluids, vortex filaments have quantized circulation.
Compound of 渦 (uzu, 'whirlpool, vortex') and 糸 (ito, 'thread'), literally 'vortex thread'. The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning.