hookworm
Concise Oxford English Dictionary © 2008 Oxford University Press:
hookworm/ˈhʊkwɜːm/
▶noun a parasitic nematode worm that attaches itself to the wall of the intestines with hook-like mouthparts. [Ancylostoma, Uncinaria, Necator, and other genera.]
'hookworm' also found in these Oxford entries:

