ichthyophthirius

noun

ich·​thy·​oph·​thir·​i·​us ˌik-thē-äf-ˈthir-ē-əs 

1

capitalized : a genus of oval ciliates (order Holotricha) that are included in a single species (I. multifiliis) and are parasitic in the skin of various freshwater fishes where they encyst and multiply causing a severe and sometimes fatal inflammation

2

: ich