The free-swimming, tailed larval stage of a parasitic flatworm, specifically a fluke; the stage that follows the redia.

The free-swimming ciliated larva of a fluke or similar flatworm, such as the blood fluke [[血吸虫|血吸蟲|xue4 xi1 chong2]], which hatches from an egg and must find a snail host to continue its life cycle.

twisting and turning in a coiled or wriggling manner