onc-
combining form 
or onco- also onch- or oncho- or onci-
Etymology: New Latin, from Greek onkos barbed hook — more at angle 
1. : barb : hook 
< Oncorhynchus >
< Oncidium >
< onchium >
< Onchocerca >
2. : barbed 
< Oncicola >
or onco- also onch- or oncho- or onci-
1.
< Oncorhynchus >
< Oncidium >
< onchium >
< Onchocerca >
2.
< Oncicola >