Real Dictionary

filariasis in American English
a disease caused by filarial worms transmitted by mosquitoes: the worms invade lymphatic vessels and lymphoid tissue, causing chronic swelling of the lower extremities and other parts of the body
noun: infection by filarial worms in the blood and lymph channels, lymph glands, and other tissues, the various species causing skin swellings, blindness, or elephantiasis if untreated

filariasis in British English
noun: a disease common in tropical and subtropical countries resulting from infestation of the lymphatic system with the nematode worms Wuchereria bancrofti or Brugia malayi, transmitted by mosquitoes: characterized by inflammation and obstruction of the lympha